/*
* Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Redis nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "server.h"
#include "sha1.h"
#include "rand.h"
#include "cluster.h"
#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>
#include <ctype.h>
#include <math.h>
char *redisProtocolToLuaType_Int(lua_State *lua, char *reply);
char *redisProtocolToLuaType_Bulk(lua_State *lua, char *reply);
char *redisProtocolToLuaType_Status(lua_State *lua, char *reply);
char *redisProtocolToLuaType_Error(lua_State *lua, char *reply);
char *redisProtocolToLuaType_MultiBulk(lua_State *lua, char *reply);
int redis_math_random (lua_State *L);
int redis_math_randomseed (lua_State *L);
void ldbInit(void);
void ldbDisable(client *c);
void ldbEnable(client *c);
void evalGenericCommandWithDebugging(client *c, int evalsha);
void luaLdbLineHook(lua_State *lua, lua_Debug *ar);
void ldbLog(sds entry);
void ldbLogRedisReply(char *reply);
sds ldbCatStackValue(sds s, lua_State *lua, int idx);
/* Debugger shared state is stored inside this global structure. */
#define LDB_BREAKPOINTS_MAX 64 /* Max number of breakpoints. */
#define LDB_MAX_LEN_DEFAULT 256 /* Default len limit for replies / var dumps. */
struct ldbState {
int fd; /* Socket of the debugging client. */
int active; /* Are we debugging EVAL right now? */
int forked; /* Is this a fork()ed debugging session? */
list *logs; /* List of messages to send to the client. */
list *traces; /* Messages about Redis commands executed since last stop.*/
list *children; /* All forked debugging sessions pids. */
int bp[LDB_BREAKPOINTS_MAX]; /* An array of breakpoints line numbers. */
int bpcount; /* Number of valid entries inside bp. */
int step; /* Stop at next line ragardless of breakpoints. */
int luabp; /* Stop at next line because redis.breakpoint() was called. */
sds *src; /* Lua script source code split by line. */
int lines; /* Number of lines in 'src'. */
int currentline; /* Current line number. */
sds cbuf; /* Debugger client command buffer. */
size_t maxlen; /* Max var dump / reply length. */
int maxlen_hint_sent; /* Did we already hint about "set maxlen"? */
} ldb;
/* ---------------------------------------------------------------------------
* Utility functions.
* ------------------------------------------------------------------------- */
/* Perform the SHA1 of the input string. We use this both for hashing script
* bodies in order to obtain the Lua function name, and in the implementation
* of redis.sha1().
*
* 'digest' should point to a 41 bytes buffer: 40 for SHA1 converted into an
* hexadecimal number, plus 1 byte for null term. */
void sha1hex(char *digest, char *script, size_t len) {
SHA1_CTX ctx;
unsigned char hash[20];
char *cset = "0123456789abcdef";
int j;
SHA1Init(&ctx);
SHA1Update(&ctx,(unsigned char*)script,len);
SHA1Final(hash,&ctx);
for (j = 0; j < 20; j++) {
digest[j*2] = cset[((hash[j]&0xF0)>>4)];
digest[j*2+1] = cset[(hash[j]&0xF)];
}
digest[40] = '\0';
}
/* ---------------------------------------------------------------------------
* Redis reply to Lua type conversion functions.
* ------------------------------------------------------------------------- */
/* Take a Redis reply in the Redis protocol format and convert it into a
* Lua type. Thanks to this function, and the introduction of not connected
* clients, it is trivial to implement the redis() lua function.
*
* Basically we take the arguments, execute the Redis command in the context
* of a non connected client, then take the generated reply and convert it
* into a suitable Lua type. With this trick the scripting feature does not
* need the introduction of a full Redis internals API. The script
* is like a normal client that bypasses all the slow I/O paths.
*
* Note: in this function we do not do any sanity check as the reply is
* generated by Redis directly. This allows us to go faster.
*
* Errors are returned as a table with a single 'err' field set to the
* error string.
*/
char *redisProtocolToLuaType(lua_State *lua, char* reply) {
char *p = reply;
switch(*p) {
case ':': p = redisProtocolToLuaType_Int(lua,reply); break;
case '$': p = redisProtocolToLuaType_Bulk(lua,reply); break;
case '+': p = redisProtocolToLuaType_Status(lua,reply); break;
case '-': p = redisProtocolToLuaType_Error(lua,reply); break;
case '*': p = redisProtocolToLuaType_MultiBulk(lua,reply); break;
}
return p;
}
char *redisProtocolToLuaType_Int(lua_State *lua, char *reply) {
char *p = strchr(reply+1,'\r');
long long value;
string2ll(reply+1,p-reply-1,&value);
lua_pushnumber(lua,(lua_Number)value);
return p+2;
}
char *redisProtocolToLuaType_Bulk(lua_State *lua, char *reply) {
char *p = strchr(reply+1,'\r');
long long bulklen;
string2ll(reply+1,p-reply-1,&bulklen);
if (bulklen == -1) {
lua_pushboolean(lua,0);
return p+2;
} else {
lua_pushlstring(lua,p+2,bulklen);
return p+2+bulklen+2;
}
}
char *redisProtocolToLuaType_Status(lua_State *lua, char *reply) {
char *p = strchr(reply+1,'\r');
lua_newtable(lua);
lua_pushstring(lua,"ok");
lua_pushlstring(lua,reply+1,p-reply-1);
lua_settable(lua,-3);
return p+2;
}
char *redisProtocolToLuaType_Error(lua_State *lua, char *reply) {
char *p = strchr(reply+1,'\r');
lua_newtable(lua);
lua_pushstring(lua,"err");
lua_pushlstring(lua,reply+1,p-reply-1);
lua_settable(lua,-3);
return p+2;
}
char *redisProtocolToLuaType_MultiBulk(lua_State *lua, char *reply) {
char *p = strchr(reply+1,'\r');
long long mbulklen;
int j = 0;
string2ll(reply+1,p-reply-1,&mbulklen);
p += 2;
if (mbulklen == -1) {
lua_pushboolean(lua,0);
return p;
}
lua_newtable(lua);
for (j = 0; j < mbulklen; j++) {
lua_pushnumber(lua,j+1);
p = redisProtocolToLuaType(lua,p);
lua_settable(lua,-3);
}
return p;
}
/* This function is used in order to push an error on the Lua stack in the
* format used by redis.pcall to return errors, which is a lua table
* with a single "err" field set to the error string. Note that this
* table is never a valid reply by proper commands, since the returned
* tables are otherwise always indexed by integers, never by strings. */
void luaPushError(lua_State *lua, char *error) {
lua_Debug dbg;
/* If debugging is active and in step mode, log errors resulting from
* Redis commands. */
if (ldb.active && ldb.step) {
ldbLog(sdscatprintf(sdsempty(),"<error> %s",error));
}
lua_newtable(lua);
lua_pushstring(lua,"err");
/* Attempt to figure out where this function was called, if possible */
if(lua_getstack(lua, 1, &dbg) && lua_getinfo(lua, "nSl", &dbg)) {
sds msg = sdscatprintf(sdsempty(), "%s: %d: %s",
dbg.source, dbg.currentline, error);
lua_pushstring(lua, msg);
sdsfree(msg);
} else {
lua_pushstring(lua, error);
}
lua_settable(lua,-3);
}
/* In case the error set into the Lua stack by luaPushError() was generated
* by the non-error-trapping version of redis.pcall(), which is redis.call(),
* this function will raise the Lua error so that the execution of the
* script will be halted. */
int luaRaiseError(lua_State *lua) {
lua_pushstring(lua,"err");
lua_gettable(lua,-2);
return lua_error(lua);
}
/* Sort the array currently in the stack. We do this to make the output
* of commands like KEYS or SMEMBERS something deterministic when called
* from Lua (to play well with AOf/replication).
*
* The array is sorted using table.sort itself, and assuming all the
* list elements are strings. */
void luaSortArray(lua_State *lua) {
/* Initial Stack: array */
lua_getglobal(lua,"table");
lua_pushstring(lua,"sort");
lua_gettable(lua,-2); /* Stack: array, table, table.sort */
lua_pushvalue(lua,-3); /* Stack: array, table, table.sort, array */
if (lua_pcall(lua,1,0,0)) {
/* Stack: array, table, error */
/* We are not interested in the error, we assume that the problem is
* that there are 'false' elements inside the array, so we try
* again with a slower function but able to handle this case, that
* is: table.sort(table, __redis__compare_helper) */
lua_pop(lua,1); /* Stack: array, table */
lua_pushstring(lua,"sort"); /* Stack: array, table, sort */
lua_gettable(lua,-2); /* Stack: array, table, table.sort */
lua_pushvalue(lua,-3); /* Stack: array, table, table.sort, array */
lua_getglobal(lua,"__redis__compare_helper");
/* Stack: array, table, table.sort, array, __redis__compare_helper */
lua_call(lua,2,0);
}
/* Stack: array (sorted), table */
lua_pop(lua,1); /* Stack: array (sorted) */
}
/* ---------------------------------------------------------------------------
* Lua reply to Redis reply conversion functions.
* ------------------------------------------------------------------------- */
void luaReplyToRedisReply(client *c, lua_State *lua) {
int t = lua_type(lua,-1);
switch(t) {
case LUA_TSTRING:
addReplyBulkCBuffer(c,(char*)lua_tostring(lua,-1),lua_strlen(lua,-1));
break;
case LUA_TBOOLEAN:
addReply(c,lua_toboolean(lua,-1) ? shared.cone : shared.nullbulk);
break;
case LUA_TNUMBER:
addReplyLongLong(c,(long long)lua_tonumber(lua,-1));
break;
case LUA_TTABLE:
/* We need to check if it is an array, an error, or a status reply.
* Error are returned as a single element table with 'err' field.
* Status replies are returned as single element table with 'ok'
* field. */
lua_pushstring(lua,"err");
lua_gettable(lua,-2);
t = lua_type(lua,-1);
if (t == LUA_TSTRING) {
sds err = sdsnew(lua_tostring(lua,-1));
sdsmapchars(err,"\r\n"," ",2);
addReplySds(c,sdscatprintf(sdsempty(),"-%s\r\n",err));
sdsfree(err);
lua_pop(lua,2);
return;
}
lua_pop(lua,1);
lua_pushstring(lua,"ok");
lua_gettable(lua,-2);
t = lua_type(lua,-1);
if (t == LUA_TSTRING) {
sds ok = sdsnew(lua_tostring(lua,-1));
sdsmapchars(ok,"\r\n"," ",2);
addReplySds(c,sdscatprintf(sdsempty(),"+%s\r\n",ok));
sdsfree(ok);
lua_pop(lua,1);
} else {
void *replylen = addDeferredMultiBulkLength(c);
int j = 1, mbulklen = 0;
lua_pop(lua,1); /* Discard the 'ok' field value we popped */
while(1) {
lua_pushnumber(lua,j++);
lua_gettable(lua,-2);
t = lua_type(lua,-1);
if (t == LUA_TNIL) {
lua_pop(lua,1);
break;
}
luaReplyToRedisReply(c, lua);
mbulklen++;
}
setDeferredMultiBulkLength(c,replylen,mbulklen);
}
break;
default:
addReply(c,shared.nullbulk);
}
lua_pop(lua,1);
}
/* ---------------------------------------------------------------------------
* Lua redis.* functions implementations.
* ------------------------------------------------------------------------- */
#define LUA_CMD_OBJCACHE_SIZE 32
#define LUA_CMD_OBJCACHE_MAX_LEN 64
int luaRedisGenericCommand(lua_State *lua, int raise_error) {
int j, argc = lua_gettop(lua);
struct redisCommand *cmd;
client *c = server.lua_client;
sds reply;
/* Cached across calls. */
static robj **argv = NULL;
static int argv_size = 0;
static robj *cached_objects[LUA_CMD_OBJCACHE_SIZE];
static size_t cached_objects_len[LUA_CMD_OBJCACHE_SIZE];
static int inuse = 0; /* Recursive calls detection. */
/* By using Lua debug hooks it is possible to trigger a recursive call
* to luaRedisGenericCommand(), which normally should never happen.
* To make this function reentrant is futile and makes it slower, but
* we should at least detect such a misuse, and abort. */
if (inuse) {
char *recursion_warning =
"luaRedisGenericCommand() recursive call detected. "
"Are you doing funny stuff with Lua debug hooks?";
serverLog(LL_WARNING,"%s",recursion_warning);
luaPushError(lua,recursion_warning);
return 1;
}
inuse++;
/* Require at least one argument */
if (argc == 0) {
luaPushError(lua,
"Please specify at least one argument for redis.call()");
inuse--;
return raise_error ? luaRaiseError(lua) : 1;
}
/* Build the arguments vector */
if (argv_size < argc) {
argv = zrealloc(argv,sizeof(robj*)*argc);
argv_size = argc;
}
for (j = 0; j < argc; j++) {
char *obj_s;
size_t obj_len;
char dbuf[64];
if (lua_type(lua,j+1) == LUA_TNUMBER) {
/* We can't use lua_tolstring() for number -> string conversion
* since Lua uses a format specifier that loses precision. */
lua_Number num = lua_tonumber(lua,j+1);
obj_len = snprintf(dbuf,sizeof(dbuf),"%.17g",(double)num);
obj_s = dbuf;
} else {
obj_s = (char*)lua_tolstring(lua,j+1,&obj_len);
if (obj_s == NULL) break; /* Not a string. */
}
/* Try to use a cached object. */
if (j < LUA_CMD_OBJCACHE_SIZE && cached_objects[j] &&
cached_objects_len[j] >= obj_len)
{
sds s = cached_objects[j]->ptr;
argv[j] = cached_objects[j];
cached_objects[j] = NULL;
memcpy(s,obj_s,obj_len+1);
sdssetlen(s, obj_len);
} else {
argv[j] = createStringObject(obj_s, obj_len);
}
}
/* Check if one of the arguments passed by the Lua script
* is not a string or an integer (lua_isstring() return true for
* integers as well). */
if (j != argc) {
j--;
while (j >= 0) {
decrRefCount(argv[j]);
j--;
}
luaPushError(lua,
"Lua redis() command arguments must be strings or integers");
inuse--;
return raise_error ? luaRaiseError(lua) : 1;
}
/* Setup our fake client for command execution */
c->argv = argv;
c->argc = argc;
/* Log the command if debugging is active. */
if (ldb.active && ldb.step) {
sds cmdlog = sdsnew("<redis>");
for (j = 0; j < c->argc; j++) {
if (j == 10) {
cmdlog = sdscatprintf(cmdlog," ... (%d more)",
c->argc-j-1);
} else {
cmdlog = sdscatlen(cmdlog," ",1);
cmdlog = sdscatsds(cmdlog,c->argv[j]->ptr);
}
}
ldbLog(cmdlog);
}
/* Command lookup */
cmd = lookupCommand(argv[0]->ptr);
if (!cmd || ((cmd->arity > 0 && cmd->arity != argc) ||
(argc < -cmd->arity)))
{
if (cmd)
luaPushError(lua,
"Wrong number of args calling Redis command From Lua script");
else
luaPushError(lua,"Unknown Redis command called from Lua script");
goto cleanup;
}
c->cmd = cmd;
/* There are commands that are not allowed inside scripts. */
if (cmd->flags & CMD_NOSCRIPT) {
luaPushError(lua, "This Redis command is not allowed from scripts");
goto cleanup;
}
/* Write commands are forbidden against read-only slaves, or if a
* command marked as non-deterministic was already called in the context
* of this script. */
if (cmd->flags & CMD_WRITE) {
if (server.lua_random_dirty && !server.lua_replicate_commands) {
luaPushError(lua,
"Write commands not allowed after non deterministic commands. Call redis.replicate_commands() at the start of your script in order to switch to single commands replication mode.");
goto cleanup;
} else if (server.masterhost && server.repl_slave_ro &&
!server.loading &&
!(server.lua_caller->flags & CLIENT_MASTER))
{
luaPushError(lua, shared.roslaveerr->ptr);
goto cleanup;
} else if (server.stop_writes_on_bgsave_err &&
server.saveparamslen > 0 &&
server.lastbgsave_status == C_ERR)
{
luaPushError(lua, shared.bgsaveerr->ptr);
goto cleanup;
}
}
/* If we reached the memory limit configured via maxmemory, commands that
* could enlarge the memory usage are not allowed, but only if this is the
* first write in the context of this script, otherwise we can't stop
* in the middle. */
if (server.maxmemory && server.lua_write_dirty == 0 &&
(cmd->flags & CMD_DENYOOM))
{
if (freeMemoryIfNeeded() == C_ERR) {
luaPushError(lua, shared.oomerr->ptr);
goto cleanup;
}
}
if (cmd->flags & CMD_RANDOM) server.lua_random_dirty = 1;
if (cmd->flags & CMD_WRITE) server.lua_write_dirty = 1;
/* If this is a Redis Cluster node, we need to make sure Lua is not
* trying to access non-local keys, with the exception of commands
* received from our master. */
if (server.cluster_enabled && !(server.lua_caller->flags & CLIENT_MASTER)) {
/* Duplicate relevant flags in the lua client. */
c->flags &= ~(CLIENT_READONLY|CLIENT_ASKING);
c->flags |= server.lua_caller->flags & (CLIENT_READONLY|CLIENT_ASKING);
if (getNodeByQuery(c,c->cmd,c->argv,c->argc,NULL,NULL) !=
server.cluster->myself)
{
luaPushError(lua,
"Lua script attempted to access a non local key in a "
"cluster node");
goto cleanup;
}
}
/* If we are using single commands replication, we need to wrap what
* we propagate into a MULTI/EXEC block, so that it will be atomic like
* a Lua script in the context of AOF and slaves. */
if (server.lua_replicate_commands &&
!server.lua_multi_emitted &&
server.lua_write_dirty &&
server.lua_repl != PROPAGATE_NONE)
{
execCommandPropagateMulti(server.lua_caller);
server.lua_multi_emitted = 1;
}
/* Run the command */
int call_flags = CMD_CALL_SLOWLOG | CMD_CALL_STATS;
if (server.lua_replicate_commands) {
/* Set flags according to redis.set_repl() settings. */
if (server.lua_repl & PROPAGATE_AOF)
call_flags |= CMD_CALL_PROPAGATE_AOF;
if (server.lua_repl & PROPAGATE_REPL)
call_flags |= CMD_CALL_PROPAGATE_REPL;
}
call(c,call_flags);
/* Convert the result of the Redis command into a suitable Lua type.
* The first thing we need is to create a single string from the client
* output buffers. */
if (listLength(c->reply) == 0 && c->bufpos < PROTO_REPLY_CHUNK_BYTES) {
/* This is a fast path for the common case of a reply inside the
* client static buffer. Don't create an SDS string but just use
* the client buffer directly. */
c->buf[c->bufpos] = '\0';
reply = c->buf;
c->bufpos = 0;
} else {
reply = sdsnewlen(c->buf,c->bufpos);
c->bufpos = 0;
while(listLength(c->reply)) {
sds o = listNodeValue(listFirst(c->reply));
reply = sdscatsds(reply,o);
listDelNode(c->reply,listFirst(c->reply));
}
}
if (raise_error && reply[0] != '-') raise_error = 0;
redisProtocolToLuaType(lua,reply);
/* If the debugger is active, log the reply from Redis. */
if (ldb.active && ldb.step)
ldbLogRedisReply(reply);
/* Sort the output array if needed, assuming it is a non-null multi bulk
* reply as expected. */
if ((cmd->flags & CMD_SORT_FOR_SCRIPT) &&
(server.lua_replicate_commands == 0) &&
(reply[0] == '*' && reply[1] != '-')) {
luaSortArray(lua);
}
if (reply != c->buf) sdsfree(reply);
c->reply_bytes = 0;
cleanup:
/* Clean up. Command code may have changed argv/argc so we use the
* argv/argc of the client instead of the local variables. */
for (j = 0; j < c->argc; j++) {
robj *o = c->argv[j];
/* Try to cache the object in the cached_objects array.
* The object must be small, SDS-encoded, and with refcount = 1
* (we must be the only owner) for us to cache it. */
if (j < LUA_CMD_OBJCACHE_SIZE &&
o->refcount == 1 &&
(o->encoding == OBJ_ENCODING_RAW ||
o->encoding == OBJ_ENCODING_EMBSTR) &&
sdslen(o->ptr) <= LUA_CMD_OBJCACHE_MAX_LEN)
{
sds s = o->ptr;
if (cached_objects[j]) decrRefCount(cached_objects[j]);
cached_objects[j] = o;
cached_objects_len[j] = sdsalloc(s);
} else {
decrRefCount(o);
}
}
if (c->argv != argv) {
zfree(c->argv);
argv = NULL;
argv_size = 0;
}
if (raise_error) {
/* If we are here we should have an error in the stack, in the
* form of a table with an "err" field. Extract the string to
* return the plain error. */
inuse--;
return luaRaiseError(lua);
}
inuse--;
return 1;
}
/* redis.call() */
int luaRedisCallCommand(lua_State *lua) {
return luaRedisGenericCommand(lua,1);
}
/* redis.pcall() */
int luaRedisPCallCommand(lua_State *lua) {
return luaRedisGenericCommand(lua,0);
}
/* This adds redis.sha1hex(string) to Lua scripts using the same hashing
* function used for sha1ing lua scripts. */
int luaRedisSha1hexCommand(lua_State *lua) {
int argc = lua_gettop(lua);
char digest[41];
size_t len;
char *s;
if (argc != 1) {
lua_pushstring(lua, "wrong number of arguments");
return lua_error(lua);
}
s = (char*)lua_tolstring(lua,1,&len);
sha1hex(digest,s,len);
lua_pushstring(lua,digest);
return 1;
}
/* Returns a table with a single field 'field' set to the string value
* passed as argument. This helper function is handy when returning
* a Redis Protocol error or status reply from Lua:
*
* return redis.error_reply("ERR Some Error")
* return redis.status_reply("ERR Some Error")
*/
int luaRedisReturnSingleFieldTable(lua_State *lua, char *field) {
if (lua_gettop(lua) != 1 || lua_type(lua,-1) != LUA_TSTRING) {
luaPushError(lua, "wrong number or type of arguments");
return 1;
}
lua_newtable(lua);
lua_pushstring(lua, field);
lua_pushvalue(lua, -3);
lua_settable(lua, -3);
return 1;
}
/* redis.error_reply() */
int luaRedisErrorReplyCommand(lua_State *lua) {
return luaRedisReturnSingleFieldTable(lua,"err");
}
/* redis.status_reply() */
int luaRedisStatusReplyCommand(lua_State *lua) {
return luaRedisReturnSingleFieldTable(lua,"ok");
}
/* redis.replicate_commands()
*
* Turn on single commands replication if the script never called
* a write command so far, and returns true. Otherwise if the script
* already started to write, returns false and stick to whole scripts
* replication, which is our default. */
int luaRedisReplicateCommandsCommand(lua_State *lua) {
if (server.lua_write_dirty) {
lua_pushboolean(lua,0);
} else {
server.lua_replicate_commands = 1;
/* When we switch to single commands replication, we can provide
* different math.random() sequences at every call, which is what
* the user normally expects. */
redisSrand48(rand());
lua_pushboolean(lua,1);
}
return 1;
}
/* redis.breakpoint()
*
* Allows to stop execution during a debuggign session from within
* the Lua code implementation, like if a breakpoint was set in the code
* immediately after the function. */
int luaRedisBreakpointCommand(lua_State *lua) {
if (ldb.active) {
ldb.luabp = 1;
lua_pushboolean(lua,1);
} else {
lua_pushboolean(lua,0);
}
return 1;
}
/* redis.debug()
*
* Log a string message into the output console.
* Can take multiple arguments that will be separated by commas.
* Nothing is returned to the caller. */
int luaRedisDebugCommand(lua_State *lua) {
if (!ldb.active) return 0;
int argc = lua_gettop(lua);
sds log = sdscatprintf(sdsempty(),"<debug> line %d: ", ldb.currentline);
while(argc--) {
log = ldbCatStackValue(log,lua,-1 - argc);
if (argc != 0) log = sdscatlen(log,", ",2);
}
ldbLog(log);
return 0;
}
/* redis.set_repl()
*
* Set the propagation of write commands executed in the context of the
* script to on/off for AOF and slaves. */
int luaRedisSetReplCommand(lua_State *lua) {
int argc = lua_gettop(lua);
int flags;
if (server.lua_replicate_commands == 0) {
lua_pushstring(lua, "You can set the replication behavior only after turning on single commands replication with redis.replicate_commands().");
return lua_error(lua);
} else if (argc != 1) {
lua_pushstring(lua, "redis.set_repl() requires two arguments.");
return lua_error(lua);
}
flags = lua_tonumber(lua,-1);
if ((flags & ~(PROPAGATE_AOF|PROPAGATE_REPL)) != 0) {
lua_pushstring(lua, "Invalid replication flags. Use REPL_AOF, REPL_SLAVE, REPL_ALL or REPL_NONE.");
return lua_error(lua);
}
server.lua_repl = flags;
return 0;
}
/* redis.log() */
int luaLogCommand(lua_State *lua) {
int j, argc = lua_gettop(lua);
int level;
sds log;
if (argc < 2) {
lua_pushstring(lua, "redis.log() requires two arguments or more.");
return lua_error(lua);
} else if (!lua_isnumber(lua,-argc)) {
lua_pushstring(lua, "First argument must be a number (log level).");
return lua_error(lua);
}
level = lua_tonumber(lua,-argc);
if (level < LL_DEBUG || level > LL_WARNING) {
lua_pushstring(lua, "Invalid debug level.");
return lua_error(lua);
}
/* Glue together all the arguments */
log = sdsempty();
for (j = 1; j < argc; j++) {
size_t len;
char *s;
s = (char*)lua_tolstring(lua,(-argc)+j,&len);
if (s) {
if (j != 1) log = sdscatlen(log," ",1);
log = sdscatlen(log,s,len);
}
}
serverLogRaw(level,log);
sdsfree(log);
return 0;
}
/* ---------------------------------------------------------------------------
* Lua engine initialization and reset.
* ------------------------------------------------------------------------- */
void luaLoadLib(lua_State *lua, const char *libname, lua_CFunction luafunc) {
lua_pushcfunction(lua, luafunc);
lua_pushstring(lua, libname);
lua_call(lua, 1, 0);
}
LUALIB_API int (luaopen_cjson) (lua_State *L);
LUALIB_API int (luaopen_struct) (lua_State *L);
LUALIB_API int (luaopen_cmsgpack) (lua_State *L);
LUALIB_API int (luaopen_bit) (lua_State *L);
void luaLoadLibraries(lua_State *lua) {
luaLoadLib(lua, "", luaopen_base);
luaLoadLib(lua, LUA_TABLIBNAME, luaopen_table);
luaLoadLib(lua, LUA_STRLIBNAME, luaopen_string);
luaLoadLib(lua, LUA_MATHLIBNAME, luaopen_math);
luaLoadLib(lua, LUA_DBLIBNAME, luaopen_debug);
luaLoadLib(lua, "cjson", luaopen_cjson);
luaLoadLib(lua, "struct", luaopen_struct);
luaLoadLib(lua, "cmsgpack", luaopen_cmsgpack);
luaLoadLib(lua, "bit", luaopen_bit);
#if 0 /* Stuff that we don't load currently, for sandboxing concerns. */
luaLoadLib(lua, LUA_LOADLIBNAME, luaopen_package);
luaLoadLib(lua, LUA_OSLIBNAME, luaopen_os);
#endif
}
/* Remove a functions that we don't want to expose to the Redis scripting
* environment. */
void luaRemoveUnsupportedFunctions(lua_State *lua) {
lua_pushnil(lua);
lua_setglobal(lua,"loadfile");
}
/* This function installs metamethods in the global table _G that prevent
* the creation of globals accidentally.
*
* It should be the last to be called in the scripting engine initialization
* sequence, because it may interact with creation of globals. */
void scriptingEnableGlobalsProtection(lua_State *lua) {
char *s[32];
sds code = sdsempty();
int j = 0;
/* strict.lua from: http://metalua.luaforge.net/src/lib/strict.lua.html.
* Modified to be adapted to Redis. */
s[j++]="local dbg=debug\n";
s[j++]="local mt = {}\n";
s[j++]="setmetatable(_G, mt)\n";
s[j++]="mt.__newindex = function (t, n, v)\n";
s[j++]=" if dbg.getinfo(2) then\n";
s[j++]=" local w = dbg.getinfo(2, \"S\").what\n";
s[j++]=" if w ~= \"main\" and w ~= \"C\" then\n";
s[j++]=" error(\"Script attempted to create global variable '\"..tostring(n)..\"'\", 2)\n";
s[j++]=" end\n";
s[j++]=" end\n";
s[j++]=" rawset(t, n, v)\n";
s[j++]="end\n";
s[j++]="mt.__index = function (t, n)\n";
s[j++]=" if dbg.getinfo(2) and dbg.getinfo(2, \"S\").what ~= \"C\" then\n";
s[j++]=" error(\"Script attempted to access unexisting global variable '\"..tostring(n)..\"'\", 2)\n";
s[j++]=" end\n";
s[j++]=" return rawget(t, n)\n";
s[j++]="end\n";
s[j++]="debug = nil\n";
s[j++]=NULL;
for (j = 0; s[j] != NULL; j++) code = sdscatlen(code,s[j],strlen(s[j]));
luaL_loadbuffer(lua,code,sdslen(code),"@enable_strict_lua");
lua_pcall(lua,0,0,0);
sdsfree(code);
}
/* Initialize the scripting environment.
*
* This function is called the first time at server startup with
* the 'setup' argument set to 1.
*
* It can be called again multiple times during the lifetime of the Redis
* process, with 'setup' set to 0, and following a scriptingRelease() call,
* in order to reset the Lua scripting environment.
*
* However it is simpler to just call scriptingReset() that does just that. */
void scriptingInit(int setup) {
lua_State *lua = lua_open();
if (setup) {
server.lua_client = NULL;
server.lua_caller = NULL;
server.lua_timedout = 0;
server.lua_always_replicate_commands = 0; /* Only DEBUG can change it.*/
server.lua_time_limit = LUA_SCRIPT_TIME_LIMIT;
ldbInit();
}
luaLoadLibraries(lua);
luaRemoveUnsupportedFunctions(lua);
/* Initialize a dictionary we use to map SHAs to scripts.
* This is useful for replication, as we need to replicate EVALSHA
* as EVAL, so we need to remember the associated script. */
server.lua_scripts = dictCreate(&shaScriptObjectDictType,NULL);
/* Register the redis commands table and fields */
lua_newtable(lua);
/* redis.call */
lua_pushstring(lua,"call");
lua_pushcfunction(lua,luaRedisCallCommand);
lua_settable(lua,-3);
/* redis.pcall */
lua_pushstring(lua,"pcall");
lua_pushcfunction(lua,luaRedisPCallCommand);
lua_settable(lua,-3);
/* redis.log and log levels. */
lua_pushstring(lua,"log");
lua_pushcfunction(lua,luaLogCommand);
lua_settable(lua,-3);
lua_pushstring(lua,"LOG_DEBUG");
lua_pushnumber(lua,LL_DEBUG);
lua_settable(lua,-3);
lua_pushstring(lua,"LOG_VERBOSE");
lua_pushnumber(lua,LL_VERBOSE);
lua_settable(lua,-3);
lua_pushstring(lua,"LOG_NOTICE");
lua_pushnumber(lua,LL_NOTICE);
lua_settable(lua,-3);
lua_pushstring(lua,"LOG_WARNING");
lua_pushnumber(lua,LL_WARNING);
lua_settable(lua,-3);
/* redis.sha1hex */
lua_pushstring(lua, "sha1hex");
lua_pushcfunction(lua, luaRedisSha1hexCommand);
lua_settable(lua, -3);
/* redis.error_reply and redis.status_reply */
lua_pushstring(lua, "error_reply");
lua_pushcfunction(lua, luaRedisErrorReplyCommand);
lua_settable(lua, -3);
lua_pushstring(lua, "status_reply");
lua_pushcfunction(lua, luaRedisStatusReplyCommand);
lua_settable(lua, -3);
/* redis.replicate_commands */
lua_pushstring(lua, "replicate_commands");
lua_pushcfunction(lua, luaRedisReplicateCommandsCommand);
lua_settable(lua, -3);
/* redis.set_repl and associated flags. */
lua_pushstring(lua,"set_repl");
lua_pushcfunction(lua,luaRedisSetReplCommand);
lua_settable(lua,-3);
lua_pushstring(lua,"REPL_NONE");
lua_pushnumber(lua,PROPAGATE_NONE);
lua_settable(lua,-3);
lua_pushstring(lua,"REPL_AOF");
lua_pushnumber(lua,PROPAGATE_AOF);
lua_settable(lua,-3);
lua_pushstring(lua,"REPL_SLAVE");
lua_pushnumber(lua,PROPAGATE_REPL);
lua_settable(lua,-3);
lua_pushstring(lua,"REPL_ALL");
lua_pushnumber(lua,PROPAGATE_AOF|PROPAGATE_REPL);
lua_settable(lua,-3);
/* redis.breakpoint */
lua_pushstring(lua,"breakpoint");
lua_pushcfunction(lua,luaRedisBreakpointCommand);
lua_settable(lua,-3);
/* redis.debug */
lua_pushstring(lua,"debug");
lua_pushcfunction(lua,luaRedisDebugCommand);
lua_settable(lua,-3);
/* Finally set the table as 'redis' global var. */
lua_setglobal(lua,"redis");
/* Replace math.random and math.randomseed with our implementations. */
lua_getglobal(lua,"math");
lua_pushstring(lua,"random");
lua_pushcfunction(lua,redis_math_random);
lua_settable(lua,-3);
lua_pushstring(lua,"randomseed");
lua_pushcfunction(lua,redis_math_randomseed);
lua_settable(lua,-3);
lua_setglobal(lua,"math");
/* Add a helper function that we use to sort the multi bulk output of non
* deterministic commands, when containing 'false' elements. */
{
char *compare_func = "function __redis__compare_helper(a,b)\n"
" if a == false then a = '' end\n"
" if b == false then b = '' end\n"
" return a<b\n"
"end\n";
luaL_loadbuffer(lua,compare_func,strlen(compare_func),"@cmp_func_def");
lua_pcall(lua,0,0,0);
}
/* Add a helper function we use for pcall error reporting.
* Note that when the error is in the C function we want to report the
* information about the caller, that's what makes sense from the point
* of view of the user debugging a script. */
{
char *errh_func = "local dbg = debug\n"
"function __redis__err__handler(err)\n"
" local i = dbg.getinfo(2,'nSl')\n"
" if i and i.what == 'C' then\n"
" i = dbg.getinfo(3,'nSl')\n"
" end\n"
" if i then\n"
" return i.source .. ':' .. i.currentline .. ': ' .. err\n"
" else\n"
" return err\n"
" end\n"
"end\n";
luaL_loadbuffer(lua,errh_func,strlen(errh_func),"@err_handler_def");
lua_pcall(lua,0,0,0);
}
/* Create the (non connected) client that we use to execute Redis commands
* inside the Lua interpreter.
* Note: there is no need to create it again when this function is called
* by scriptingReset(). */
if (server.lua_client == NULL) {
server.lua_client = createClient(-1);
server.lua_client->flags |= CLIENT_LUA;
}
/* Lua beginners often don't use "local", this is likely to introduce
* subtle bugs in their code. To prevent problems we protect accesses
* to global variables. */
scriptingEnableGlobalsProtection(lua);
server.lua = lua;
}
/* Release resources related to Lua scripting.
* This function is used in order to reset the scripting environment. */
void scriptingRelease(void) {
dictRelease(server.lua_scripts);
lua_close(server.lua);
}
void scriptingReset(void) {
scriptingRelease();
scriptingInit(0);
}
/* Set an array of Redis String Objects as a Lua array (table) stored into a
* global variable. */
void luaSetGlobalArray(lua_State *lua, char *var, robj **elev, int elec) {
int j;
lua_newtable(lua);
for (j = 0; j < elec; j++) {
lua_pushlstring(lua,(char*)elev[j]->ptr,sdslen(elev[j]->ptr));
lua_rawseti(lua,-2,j+1);
}
lua_setglobal(lua,var);
}
/* ---------------------------------------------------------------------------
* Redis provided math.random
* ------------------------------------------------------------------------- */
/* We replace math.random() with our implementation that is not affected
* by specific libc random() implementations and will output the same sequence
* (for the same seed) in every arch. */
/* The following implementation is the one shipped with Lua itself but with
* rand() replaced by redisLrand48(). */
int redis_math_random (lua_State *L) {
/* the `%' avoids the (rare) case of r==1, and is needed also because on
some systems (SunOS!) `rand()' may return a value larger than RAND_MAX */
lua_Number r = (lua_Number)(redisLrand48()%REDIS_LRAND48_MAX) /
(lua_Number)REDIS_LRAND48_MAX;
switch (lua_gettop(L)) { /* check number of arguments */
case 0: { /* no arguments */
lua_pushnumber(L, r); /* Number between 0 and 1 */
break;
}
case 1: { /* only upper limit */
int u = luaL_checkint(L, 1);
luaL_argcheck(L, 1<=u, 1, "interval is empty");
lua_pushnumber(L, floor(r*u)+1); /* int between 1 and `u' */
break;
}
case 2: { /* lower and upper limits */
int l = luaL_checkint(L, 1);
int u = luaL_checkint(L, 2);
luaL_argcheck(L, l<=u, 2, "interval is empty");
lua_pushnumber(L, floor(r*(u-l+1))+l); /* int between `l' and `u' */
break;
}
default: return luaL_error(L, "wrong number of arguments");
}
return 1;
}
int redis_math_randomseed (lua_State *L) {
redisSrand48(luaL_checkint(L, 1));
return 0;
}
/* ---------------------------------------------------------------------------
* EVAL and SCRIPT commands implementation
* ------------------------------------------------------------------------- */
/* Define a lua function with the specified function name and body.
* The function name musts be a 42 characters long string, since all the
* functions we defined in the Lua context are in the form:
*
* f_<hex sha1 sum>
*
* On success C_OK is returned, and nothing is left on the Lua stack.
* On error C_ERR is returned and an appropriate error is set in the
* client context. */
int luaCreateFunction(client *c, lua_State *lua, char *funcname, robj *body) {
sds funcdef = sdsempty();
funcdef = sdscat(funcdef,"function ");
funcdef = sdscatlen(funcdef,funcname,42);
funcdef = sdscatlen(funcdef,"() ",3);
funcdef = sdscatlen(funcdef,body->ptr,sdslen(body->ptr));
funcdef = sdscatlen(funcdef," end",4);
if (luaL_loadbuffer(lua,funcdef,sdslen(funcdef),"@user_script")) {
addReplyErrorFormat(c,"Error compiling script (new function): %s\n",
lua_tostring(lua,-1));
lua_pop(lua,1);
sdsfree(funcdef);
return C_ERR;
}
sdsfree(funcdef);
if (lua_pcall(lua,0,0,0)) {
addReplyErrorFormat(c,"Error running script (new function): %s\n",
lua_tostring(lua,-1));
lua_pop(lua,1);
return C_ERR;
}
/* We also save a SHA1 -> Original script map in a dictionary
* so that we can replicate / write in the AOF all the
* EVALSHA commands as EVAL using the original script. */
{
int retval = dictAdd(server.lua_scripts,
sdsnewlen(funcname+2,40),body);
serverAssertWithInfo(c,NULL,retval == DICT_OK);
incrRefCount(body);
}
return C_OK;
}
/* This is the Lua script "count" hook that we use to detect scripts timeout. */
void luaMaskCountHook(lua_State *lua, lua_Debug *ar) {
long long elapsed;
UNUSED(ar);
UNUSED(lua);
elapsed = mstime() - server.lua_time_start;
if (elapsed >= server.lua_time_limit && server.lua_timedout == 0) {
serverLog(LL_WARNING,"Lua slow script detected: still in execution after %lld milliseconds. You can try killing the script using the SCRIPT KILL command.",elapsed);
server.lua_timedout = 1;
/* Once the script timeouts we reenter the event loop to permit others
* to call SCRIPT KILL or SHUTDOWN NOSAVE if needed. For this reason
* we need to mask the client executing the script from the event loop.
* If we don't do that the client may disconnect and could no longer be
* here when the EVAL command will return. */
aeDeleteFileEvent(server.el, server.lua_caller->fd, AE_READABLE);
}
if (server.lua_timedout) processEventsWhileBlocked();
if (server.lua_kill) {
serverLog(LL_WARNING,"Lua script killed by user with SCRIPT KILL.");
lua_pushstring(lua,"Script killed by user with SCRIPT KILL...");
lua_error(lua);
}
}
void evalGenericCommand(client *c, int evalsha) {
lua_State *lua = server.lua;
char funcname[43];
long long numkeys;
int delhook = 0, err;
/* When we replicate whole scripts, we want the same PRNG sequence at
* every call so that our PRNG is not affected by external state. */
redisSrand48(0);
/* We set this flag to zero to remember that so far no random command
* was called. This way we can allow the user to call commands like
* SRANDMEMBER or RANDOMKEY from Lua scripts as far as no write command
* is called (otherwise the replication and AOF would end with non
* deterministic sequences).
*
* Thanks to this flag we'll raise an error every time a write command
* is called after a random command was used. */
server.lua_random_dirty = 0;
server.lua_write_dirty = 0;
server.lua_replicate_commands = server.lua_always_replicate_commands;
server.lua_multi_emitted = 0;
server.lua_repl = PROPAGATE_AOF|PROPAGATE_REPL;
/* Get the number of arguments that are keys */
if (getLongLongFromObjectOrReply(c,c->argv[2],&numkeys,NULL) != C_OK)
return;
if (numkeys > (c->argc - 3)) {
addReplyError(c,"Number of keys can't be greater than number of args");
return;
} else if (numkeys < 0) {
addReplyError(c,"Number of keys can't be negative");
return;
}
/* We obtain the script SHA1, then check if this function is already
* defined into the Lua state */
funcname[0] = 'f';
funcname[1] = '_';
if (!evalsha) {
/* Hash the code if this is an EVAL call */
sha1hex(funcname+2,c->argv[1]->ptr,sdslen(c->argv[1]->ptr));
} else {
/* We already have the SHA if it is a EVALSHA */
int j;
char *sha = c->argv[1]->ptr;
/* Convert to lowercase. We don't use tolower since the function
* managed to always show up in the profiler output consuming
* a non trivial amount of time. */
for (j = 0; j < 40; j++)
funcname[j+2] = (sha[j] >= 'A' && sha[j] <= 'Z') ?
sha[j]+('a'-'A') : sha[j];
funcname[42] = '\0';
}
/* Push the pcall error handler function on the stack. */
lua_getglobal(lua, "__redis__err__handler");
/* Try to lookup the Lua function */
lua_getglobal(lua, funcname);
if (lua_isnil(lua,-1)) {
lua_pop(lua,1); /* remove the nil from the stack */
/* Function not defined... let's define it if we have the
* body of the function. If this is an EVALSHA call we can just
* return an error. */
if (evalsha) {
lua_pop(lua,1); /* remove the error handler from the stack. */
addReply(c, shared.noscripterr);
return;
}
if (luaCreateFunction(c,lua,funcname,c->argv[1]) == C_ERR) {
lua_pop(lua,1); /* remove the error handler from the stack. */
/* The error is sent to the client by luaCreateFunction()
* itself when it returns C_ERR. */
return;
}
/* Now the following is guaranteed to return non nil */
lua_getglobal(lua, funcname);
serverAssert(!lua_isnil(lua,-1));
}
/* Populate the argv and keys table accordingly to the arguments that
* EVAL received. */
luaSetGlobalArray(lua,"KEYS",c->argv+3,numkeys);
luaSetGlobalArray(lua,"ARGV",c->argv+3+numkeys,c->argc-3-numkeys);
/* Select the right DB in the context of the Lua client */
selectDb(server.lua_client,c->db->id);
/* Set a hook in order to be able to stop the script execution if it
* is running for too much time.
* We set the hook only if the time limit is enabled as the hook will
* make the Lua script execution slower.
*
* If we are debugging, we set instead a "line" hook so that the
* debugger is call-back at every line executed by the script. */
server.lua_caller = c;
server.lua_time_start = mstime();
server.lua_kill = 0;
if (server.lua_time_limit > 0 && server.masterhost == NULL &&
ldb.active == 0)
{
lua_sethook(lua,luaMaskCountHook,LUA_MASKCOUNT,100000);
delhook = 1;
} else if (ldb.active) {
lua_sethook(server.lua,luaLdbLineHook,LUA_MASKLINE|LUA_MASKCOUNT,100000);
delhook = 1;
}
/* At this point whether this script was never seen before or if it was
* already defined, we can call it. We have zero arguments and expect
* a single return value. */
err = lua_pcall(lua,0,1,-2);
/* Perform some cleanup that we need to do both on error and success. */
if (delhook) lua_sethook(lua,NULL,0,0); /* Disable hook */
if (server.lua_timedout) {
server.lua_timedout = 0;
/* Restore the readable handler that was unregistered when the
* script timeout was detected. */
aeCreateFileEvent(server.el,c->fd,AE_READABLE,
readQueryFromClient,c);
}
server.lua_caller = NULL;
/* Call the Lua garbage collector from time to time to avoid a
* full cycle performed by Lua, which adds too latency.
*
* The call is performed every LUA_GC_CYCLE_PERIOD executed commands
* (and for LUA_GC_CYCLE_PERIOD collection steps) because calling it
* for every command uses too much CPU. */
#define LUA_GC_CYCLE_PERIOD 50
{
static long gc_count = 0;
gc_count++;
if (gc_count == LUA_GC_CYCLE_PERIOD) {
lua_gc(lua,LUA_GCSTEP,LUA_GC_CYCLE_PERIOD);
gc_count = 0;
}
}
if (err) {
addReplyErrorFormat(c,"Error running script (call to %s): %s\n",
funcname, lua_tostring(lua,-1));
lua_pop(lua,2); /* Consume the Lua reply and remove error handler. */
} else {
/* On success convert the Lua return value into Redis protocol, and
* send it to * the client. */
luaReplyToRedisReply(c,lua); /* Convert and consume the reply. */
lua_pop(lua,1); /* Remove the error handler. */
}
/* If we are using single commands replication, emit EXEC if there
* was at least a write. */
if (server.lua_replicate_commands) {
preventCommandPropagation(c);
if (server.lua_multi_emitted) {
robj *propargv[1];
propargv[0] = createStringObject("EXEC",4);
alsoPropagate(server.execCommand,c->db->id,propargv,1,
PROPAGATE_AOF|PROPAGATE_REPL);
decrRefCount(propargv[0]);
}
}
/* EVALSHA should be propagated to Slave and AOF file as full EVAL, unless
* we are sure that the script was already in the context of all the
* attached slaves *and* the current AOF file if enabled.
*
* To do so we use a cache of SHA1s of scripts that we already propagated
* as full EVAL, that's called the Replication Script Cache.
*
* For repliation, everytime a new slave attaches to the master, we need to
* flush our cache of scripts that can be replicated as EVALSHA, while
* for AOF we need to do so every time we rewrite the AOF file. */
if (evalsha && !server.lua_replicate_commands) {
if (!replicationScriptCacheExists(c->argv[1]->ptr)) {
/* This script is not in our script cache, replicate it as
* EVAL, then add it into the script cache, as from now on
* slaves and AOF know about it. */
robj *script = dictFetchValue(server.lua_scripts,c->argv[1]->ptr);
replicationScriptCacheAdd(c->argv[1]->ptr);
serverAssertWithInfo(c,NULL,script != NULL);
rewriteClientCommandArgument(c,0,
resetRefCount(createStringObject("EVAL",4)));
rewriteClientCommandArgument(c,1,script);
forceCommandPropagation(c,PROPAGATE_REPL|PROPAGATE_AOF);
}
}
}
void evalCommand(client *c) {
if (!(c->flags & CLIENT_LUA_DEBUG))
evalGenericCommand(c,0);
else
evalGenericCommandWithDebugging(c,0);
}
void evalShaCommand(client *c) {
if (sdslen(c->argv[1]->ptr) != 40) {
/* We know that a match is not possible if the provided SHA is
* not the right length. So we return an error ASAP, this way
* evalGenericCommand() can be implemented without string length
* sanity check */
addReply(c, shared.noscripterr);
return;
}
if (!(c->flags & CLIENT_LUA_DEBUG))
evalGenericCommand(c,1);
else {
addReplyError(c,"Please use EVAL instead of EVALSHA for debugging");
return;
}
}
void scriptCommand(client *c) {
if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"flush")) {
scriptingReset();
addReply(c,shared.ok);
replicationScriptCacheFlush();
server.dirty++; /* Propagating this command is a good idea. */
} else if (c->argc >= 2 && !strcasecmp(c->argv[1]->ptr,"exists")) {
int j;
addReplyMultiBulkLen(c, c->argc-2);
for (j = 2; j < c->argc; j++) {
if (dictFind(server.lua_scripts,c->argv[j]->ptr))
addReply(c,shared.cone);
else
addReply(c,shared.czero);
}
} else if (c->argc == 3 && !strcasecmp(c->argv[1]->ptr,"load")) {
char funcname[43];
sds sha;
funcname[0] = 'f';
funcname[1] = '_';
sha1hex(funcname+2,c->argv[2]->ptr,sdslen(c->argv[2]->ptr));
sha = sdsnewlen(funcname+2,40);
if (dictFind(server.lua_scripts,sha) == NULL) {
if (luaCreateFunction(c,server.lua,funcname,c->argv[2])
== C_ERR) {
sdsfree(sha);
return;
}
}
addReplyBulkCBuffer(c,funcname+2,40);
sdsfree(sha);
forceCommandPropagation(c,PROPAGATE_REPL|PROPAGATE_AOF);
} else if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"kill")) {
if (server.lua_caller == NULL) {
addReplySds(c,sdsnew("-NOTBUSY No scripts in execution right now.\r\n"));
} else if (server.lua_write_dirty) {
addReplySds(c,sdsnew("-UNKILLABLE Sorry the script already executed write commands against the dataset. You can either wait the script termination or kill the server in a hard way using the SHUTDOWN NOSAVE command.\r\n"));
} else {
server.lua_kill = 1;
addReply(c,shared.ok);
}
} else if (c->argc == 3 && !strcasecmp(c->argv[1]->ptr,"debug")) {
if (clientHasPendingReplies(c)) {
addReplyError(c,"SCRIPT DEBUG must be called outside a pipeline");
return;
}
if (!strcasecmp(c->argv[2]->ptr,"no")) {
ldbDisable(c);
addReply(c,shared.ok);
} else if (!strcasecmp(c->argv[2]->ptr,"yes")) {
ldbEnable(c);
addReply(c,shared.ok);
} else if (!strcasecmp(c->argv[2]->ptr,"sync")) {
ldbEnable(c);
addReply(c,shared.ok);
c->flags |= CLIENT_LUA_DEBUG_SYNC;
} else {
addReplyError(c,"Use SCRIPT DEBUG yes/sync/no");
}
} else {
addReplyError(c, "Unknown SCRIPT subcommand or wrong # of args.");
}
}
/* ---------------------------------------------------------------------------
* LDB: Redis Lua debugging facilities
* ------------------------------------------------------------------------- */
/* Initialize Lua debugger data structures. */
void ldbInit(void) {
ldb.fd = -1;
ldb.active = 0;
ldb.logs = listCreate();
listSetFreeMethod(ldb.logs,(void (*)(void*))sdsfree);
ldb.children = listCreate();
ldb.src = NULL;
ldb.lines = 0;
ldb.cbuf = sdsempty();
}
/* Remove all the pending messages in the specified list. */
void ldbFlushLog(list *log) {
listNode *ln;
while((ln = listFirst(log)) != NULL)
listDelNode(log,ln);
}
/* Enable debug mode of Lua scripts for this client. */
void ldbEnable(client *c) {
c->flags |= CLIENT_LUA_DEBUG;
ldbFlushLog(ldb.logs);
ldb.fd = c->fd;
ldb.step = 1;
ldb.bpcount = 0;
ldb.luabp = 0;
sdsfree(ldb.cbuf);
ldb.cbuf = sdsempty();
ldb.maxlen = LDB_MAX_LEN_DEFAULT;
ldb.maxlen_hint_sent = 0;
}
/* Exit debugging mode from the POV of client. This function is not enough
* to properly shut down a client debugging session, see ldbEndSession()
* for more information. */
void ldbDisable(client *c) {
c->flags &= ~(CLIENT_LUA_DEBUG|CLIENT_LUA_DEBUG_SYNC);
}
/* Append a log entry to the specified LDB log. */
void ldbLog(sds entry) {
listAddNodeTail(ldb.logs,entry);
}
/* A version of ldbLog() which prevents producing logs greater than
* ldb.maxlen. The first time the limit is reached an hint is generated
* to inform the user that reply trimming can be disabled using the
* debugger "maxlen" command. */
void ldbLogWithMaxLen(sds entry) {
int trimmed = 0;
if (ldb.maxlen && sdslen(entry) > ldb.maxlen) {
sdsrange(entry,0,ldb.maxlen-1);
entry = sdscatlen(entry," ...",4);
trimmed = 1;
}
ldbLog(entry);
if (trimmed && ldb.maxlen_hint_sent == 0) {
ldb.maxlen_hint_sent = 1;
ldbLog(sdsnew(
"<hint> The above reply was trimmed. Use 'maxlen 0' to disable trimming."));
}
}
/* Send ldb.logs to the debugging client as a multi-bulk reply
* consisting of simple strings. Log entries which include newlines have them
* replaced with spaces. The entries sent are also consumed. */
void ldbSendLogs(void) {
sds proto = sdsempty();
proto = sdscatfmt(proto,"*%i\r\n", (int)listLength(ldb.logs));
while(listLength(ldb.logs)) {
listNode *ln = listFirst(ldb.logs);
proto = sdscatlen(proto,"+",1);
sdsmapchars(ln->value,"\r\n"," ",2);
proto = sdscatsds(proto,ln->value);
proto = sdscatlen(proto,"\r\n",2);
listDelNode(ldb.logs,ln);
}
write(ldb.fd,proto,sdslen(proto));
sdsfree(proto);
}
/* Start a debugging session before calling EVAL implementation.
* The techique we use is to capture the client socket file descriptor,
* in order to perform direct I/O with it from within Lua hooks. This
* way we don't have to re-enter Redis in order to handle I/O.
*
* The function returns 1 if the caller should proceed to call EVAL,
* and 0 if instead the caller should abort the operation (this happens
* for the parent in a forked session, since it's up to the children
* to continue, or when fork returned an error).
*
* The caller should call ldbEndSession() only if ldbStartSession()
* returned 1. */
int ldbStartSession(client *c) {
ldb.forked = (c->flags & CLIENT_LUA_DEBUG_SYNC) == 0;
if (ldb.forked) {
pid_t cp = fork();
if (cp == -1) {
addReplyError(c,"Fork() failed: can't run EVAL in debugging mode.");
return 0;
} else if (cp == 0) {
/* Child. Let's ignore important signals handled by the parent. */
struct sigaction act;
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
act.sa_handler = SIG_IGN;
sigaction(SIGTERM, &act, NULL);
sigaction(SIGINT, &act, NULL);
/* Log the creation of the child and close the listening
* socket to make sure if the parent crashes a reset is sent
* to the clients. */
serverLog(LL_WARNING,"Redis forked for debugging eval");
closeListeningSockets(0);
} else {
/* Parent */
listAddNodeTail(ldb.children,(void*)(unsigned long)cp);
freeClientAsync(c); /* Close the client in the parent side. */
return 0;
}
} else {
serverLog(LL_WARNING,
"Redis synchronous debugging eval session started");
}
/* Setup our debugging session. */
anetBlock(NULL,ldb.fd);
anetSendTimeout(NULL,ldb.fd,5000);
ldb.active = 1;
/* First argument of EVAL is the script itself. We split it into different
* lines since this is the way the debugger accesses the source code. */
sds srcstring = sdsdup(c->argv[1]->ptr);
size_t srclen = sdslen(srcstring);
while(srclen && (srcstring[srclen-1] == '\n' ||
srcstring[srclen-1] == '\r'))
{
srcstring[--srclen] = '\0';
}
sdssetlen(srcstring,srclen);
ldb.src = sdssplitlen(srcstring,sdslen(srcstring),"\n",1,&ldb.lines);
sdsfree(srcstring);
return 1;
}
/* End a debugging session after the EVAL call with debugging enabled
* returned. */
void ldbEndSession(client *c) {
/* Emit the remaining logs and an <endsession> mark. */
ldbLog(sdsnew("<endsession>"));
ldbSendLogs();
/* If it's a fork()ed session, we just exit. */
if (ldb.forked) {
writeToClient(c->fd, c, 0);
serverLog(LL_WARNING,"Lua debugging session child exiting");
exitFromChild(0);
} else {
serverLog(LL_WARNING,
"Redis synchronous debugging eval session ended");
}
/* Otherwise let's restore client's state. */
anetNonBlock(NULL,ldb.fd);
anetSendTimeout(NULL,ldb.fd,0);
/* Close the client connectin after sending the final EVAL reply
* in order to signal the end of the debugging session. */
c->flags |= CLIENT_CLOSE_AFTER_REPLY;
/* Cleanup. */
sdsfreesplitres(ldb.src,ldb.lines);
ldb.lines = 0;
ldb.active = 0;
}
/* If the specified pid is among the list of children spawned for
* forked debugging sessions, it is removed from the children list.
* If the pid was found non-zero is returned. */
int ldbRemoveChild(pid_t pid) {
listNode *ln = listSearchKey(ldb.children,(void*)(unsigned long)pid);
if (ln) {
listDelNode(ldb.children,ln);
return 1;
}
return 0;
}
/* Return the number of children we still did not received termination
* acknowledge via wait() in the parent process. */
int ldbPendingChildren(void) {
return listLength(ldb.children);
}
/* Kill all the forked sessions. */
void ldbKillForkedSessions(void) {
listIter li;
listNode *ln;
listRewind(ldb.children,&li);
while((ln = listNext(&li))) {
pid_t pid = (unsigned long) ln->value;
serverLog(LL_WARNING,"Killing debugging session %ld",(long)pid);
kill(pid,SIGKILL);
}
listRelease(ldb.children);
ldb.children = listCreate();
}
/* Wrapper for EVAL / EVALSHA that enables debugging, and makes sure
* that when EVAL returns, whatever happened, the session is ended. */
void evalGenericCommandWithDebugging(client *c, int evalsha) {
if (ldbStartSession(c)) {
evalGenericCommand(c,evalsha);
ldbEndSession(c);
} else {
ldbDisable(c);
}
}
/* Return a pointer to ldb.src source code line, considering line to be
* one-based, and returning a special string for out of range lines. */
char *ldbGetSourceLine(int line) {
int idx = line-1;
if (idx < 0 || idx >= ldb.lines) return "<out of range source code line>";
return ldb.src[idx];
}
/* Return true if there is a breakpoint in the specified line. */
int ldbIsBreakpoint(int line) {
int j;
for (j = 0; j < ldb.bpcount; j++)
if (ldb.bp[j] == line) return 1;
return 0;
}
/* Add the specified breakpoint. Ignore it if we already reached the max.
* Returns 1 if the breakpoint was added (or was already set). 0 if there is
* no space for the breakpoint or if the line is invalid. */
int ldbAddBreakpoint(int line) {
if (line <= 0 || line > ldb.lines) return 0;
if (!ldbIsBreakpoint(line) && ldb.bpcount != LDB_BREAKPOINTS_MAX) {
ldb.bp[ldb.bpcount++] = line;
return 1;
}
return 0;
}
/* Remove the specified breakpoint, returning 1 if the operation was
* performed or 0 if there was no such breakpoint. */
int ldbDelBreakpoint(int line) {
int j;
for (j = 0; j < ldb.bpcount; j++) {
if (ldb.bp[j] == line) {
ldb.bpcount--;
memmove(ldb.bp+j,ldb.bp+j+1,ldb.bpcount-j);
return 1;
}
}
return 0;
}
/* Expect a valid multi-bulk command in the debugging client query buffer.
* On success the command is parsed and returned as an array of SDS strings,
* otherwise NULL is returned and there is to read more buffer. */
sds *ldbReplParseCommand(int *argcp) {
sds *argv = NULL;
int argc = 0;
if (sdslen(ldb.cbuf) == 0) return NULL;
/* Working on a copy is simpler in this case. We can modify it freely
* for the sake of simpler parsing. */
sds copy = sdsdup(ldb.cbuf);
char *p = copy;
/* This Redis protocol parser is a joke... just the simplest thing that
* works in this context. It is also very forgiving regarding broken
* protocol. */
/* Seek and parse *<count>\r\n. */
p = strchr(p,'*'); if (!p) goto protoerr;
char *plen = p+1; /* Multi bulk len pointer. */
p = strstr(p,"\r\n"); if (!p) goto protoerr;
*p = '\0'; p += 2;
*argcp = atoi(plen);
if (*argcp <= 0 || *argcp > 1024) goto protoerr;
/* Parse each argument. */
argv = zmalloc(sizeof(sds)*(*argcp));
argc = 0;
while(argc < *argcp) {
if (*p != '$') goto protoerr;
plen = p+1; /* Bulk string len pointer. */
p = strstr(p,"\r\n"); if (!p) goto protoerr;
*p = '\0'; p += 2;
int slen = atoi(plen); /* Length of this arg. */
if (slen <= 0 || slen > 1024) goto protoerr;
argv[argc++] = sdsnewlen(p,slen);
p += slen; /* Skip the already parsed argument. */
if (p[0] != '\r' || p[1] != '\n') goto protoerr;
p += 2; /* Skip \r\n. */
}
sdsfree(copy);
return argv;
protoerr:
sdsfreesplitres(argv,argc);
sdsfree(copy);
return NULL;
}
/* Log the specified line in the Lua debugger output. */
void ldbLogSourceLine(int lnum) {
char *line = ldbGetSourceLine(lnum);
char *prefix;
int bp = ldbIsBreakpoint(lnum);
int current = ldb.currentline == lnum;
if (current && bp)
prefix = "->#";
else if (current)
prefix = "-> ";
else if (bp)
prefix = " #";
else
prefix = " ";
sds thisline = sdscatprintf(sdsempty(),"%s%-3d %s", prefix, lnum, line);
ldbLog(thisline);
}
/* Implement the "list" command of the Lua debugger. If around is 0
* the whole file is listed, otherwise only a small portion of the file
* around the specified line is shown. When a line number is specified
* the amonut of context (lines before/after) is specified via the
* 'context' argument. */
void ldbList(int around, int context) {
int j;
for (j = 1; j <= ldb.lines; j++) {
if (around != 0 && abs(around-j) > context) continue;
ldbLogSourceLine(j);
}
}
/* Append an human readable representation of the Lua value at position 'idx'
* on the stack of the 'lua' state, to the SDS string passed as argument.
* The new SDS string with the represented value attached is returned.
* Used in order to implement ldbLogStackValue().
*
* The element is not automatically removed from the stack, nor it is
* converted to a different type. */
sds ldbCatStackValue(sds s, lua_State *lua, int idx) {
int t = lua_type(lua,idx);
switch(t) {
case LUA_TSTRING:
{
size_t strl;
char *strp = (char*)lua_tolstring(lua,idx,&strl);
s = sdscatrepr(s,strp,strl);
}
break;
case LUA_TBOOLEAN:
s = sdscat(s,lua_toboolean(lua,idx) ? "true" : "false");
break;
case LUA_TNUMBER:
s = sdscatprintf(s,"%g",(double)lua_tonumber(lua,idx));
break;
case LUA_TNIL:
s = sdscatlen(s,"nil",3);
break;
case LUA_TTABLE:
{
int expected_index = 1; /* First index we expect in an array. */
int is_array = 1; /* Will be set to null if check fails. */
/* Note: we create two representations at the same time, one
* assuming the table is an array, one assuming it is not. At the
* end we know what is true and select the right one. */
sds repr1 = sdsempty();
sds repr2 = sdsempty();
lua_pushnil(lua); /* The first key to start the iteration is nil. */
while (lua_next(lua,idx-1)) {
/* Test if so far the table looks like an array. */
if (is_array &&
(lua_type(lua,-2) != LUA_TNUMBER ||
lua_tonumber(lua,-2) != expected_index)) is_array = 0;
/* Stack now: table, key, value */
/* Array repr. */
repr1 = ldbCatStackValue(repr1,lua,-1);
repr1 = sdscatlen(repr1,"; ",2);
/* Full repr. */
repr2 = ldbCatStackValue(repr2,lua,-2);
repr2 = sdscatlen(repr2,"=",1);
repr2 = ldbCatStackValue(repr2,lua,-1);
repr2 = sdscatlen(repr2,"; ",2);
lua_pop(lua,1); /* Stack: table, key. Ready for next iteration. */
expected_index++;
}
/* Strip the last " ;" from both the representations. */
if (sdslen(repr1)) sdsrange(repr1,0,-3);
if (sdslen(repr2)) sdsrange(repr2,0,-3);
/* Select the right one and discard the other. */
s = sdscatlen(s,"{",1);
s = sdscatsds(s,is_array ? repr1 : repr2);
s = sdscatlen(s,"}",1);
sdsfree(repr1);
sdsfree(repr2);
}
break;
case LUA_TFUNCTION:
case LUA_TUSERDATA:
case LUA_TTHREAD:
case LUA_TLIGHTUSERDATA:
{
const void *p = lua_topointer(lua,idx);
char *typename = "unknown";
if (t == LUA_TFUNCTION) typename = "function";
else if (t == LUA_TUSERDATA) typename = "userdata";
else if (t == LUA_TTHREAD) typename = "thread";
else if (t == LUA_TLIGHTUSERDATA) typename = "light-userdata";
s = sdscatprintf(s,"%s@%p",typename,p);
}
break;
default:
s = sdscat(s,"<unknown-lua-type>");
break;
}
return s;
}
/* Produce a debugger log entry representing the value of the Lua object
* currently on the top of the stack. The element is ot popped nor modified.
* Check ldbCatStackValue() for the actual implementation. */
void ldbLogStackValue(lua_State *lua, char *prefix) {
sds s = sdsnew(prefix);
s = ldbCatStackValue(s,lua,-1);
ldbLogWithMaxLen(s);
}
char *ldbRedisProtocolToHuman_Int(sds *o, char *reply);
char *ldbRedisProtocolToHuman_Bulk(sds *o, char *reply);
char *ldbRedisProtocolToHuman_Status(sds *o, char *reply);
char *ldbRedisProtocolToHuman_MultiBulk(sds *o, char *reply);
/* Get Redis protocol from 'reply' and appends it in human readable form to
* the passed SDS string 'o'.
*
* Note that the SDS string is passed by reference (pointer of pointer to
* char*) so that we can return a modified pointer, as for SDS semantics. */
char *ldbRedisProtocolToHuman(sds *o, char *reply) {
char *p = reply;
switch(*p) {
case ':': p = ldbRedisProtocolToHuman_Int(o,reply); break;
case '$': p = ldbRedisProtocolToHuman_Bulk(o,reply); break;
case '+': p = ldbRedisProtocolToHuman_Status(o,reply); break;
case '-': p = ldbRedisProtocolToHuman_Status(o,reply); break;
case '*': p = ldbRedisProtocolToHuman_MultiBulk(o,reply); break;
}
return p;
}
/* The following functions are helpers for ldbRedisProtocolToHuman(), each
* take care of a given Redis return type. */
char *ldbRedisProtocolToHuman_Int(sds *o, char *reply) {
char *p = strchr(reply+1,'\r');
*o = sdscatlen(*o,reply+1,p-reply-1);
return p+2;
}
char *ldbRedisProtocolToHuman_Bulk(sds *o, char *reply) {
char *p = strchr(reply+1,'\r');
long long bulklen;
string2ll(reply+1,p-reply-1,&bulklen);
if (bulklen == -1) {
*o = sdscatlen(*o,"NULL",4);
return p+2;
} else {
*o = sdscatrepr(*o,p+2,bulklen);
return p+2+bulklen+2;
}
}
char *ldbRedisProtocolToHuman_Status(sds *o, char *reply) {
char *p = strchr(reply+1,'\r');
*o = sdscatrepr(*o,reply,p-reply);
return p+2;
}
char *ldbRedisProtocolToHuman_MultiBulk(sds *o, char *reply) {
char *p = strchr(reply+1,'\r');
long long mbulklen;
int j = 0;
string2ll(reply+1,p-reply-1,&mbulklen);
p += 2;
if (mbulklen == -1) {
*o = sdscatlen(*o,"NULL",4);
return p;
}
*o = sdscatlen(*o,"[",1);
for (j = 0; j < mbulklen; j++) {
p = ldbRedisProtocolToHuman(o,p);
if (j != mbulklen-1) *o = sdscatlen(*o,",",1);
}
*o = sdscatlen(*o,"]",1);
return p;
}
/* Log a Redis reply as debugger output, in an human readable format.
* If the resulting string is longer than 'len' plus a few more chars
* used as prefix, it gets truncated. */
void ldbLogRedisReply(char *reply) {
sds log = sdsnew("<reply> ");
ldbRedisProtocolToHuman(&log,reply);
ldbLogWithMaxLen(log);
}
/* Implements the "print <var>" command of the Lua debugger. It scans for Lua
* var "varname" starting from the current stack frame up to the top stack
* frame. The first matching variable is printed. */
void ldbPrint(lua_State *lua, char *varname) {
lua_Debug ar;
int l = 0; /* Stack level. */
while (lua_getstack(lua,l,&ar) != 0) {
l++;
const char *name;
int i = 1; /* Variable index. */
while((name = lua_getlocal(lua,&ar,i)) != NULL) {
i++;
if (strcmp(varname,name) == 0) {
ldbLogStackValue(lua,"<value> ");
lua_pop(lua,1);
return;
} else {
lua_pop(lua,1); /* Discard the var name on the stack. */
}
}
}
/* Let's try with global vars in two selected cases */
if (!strcmp(varname,"ARGV") || !strcmp(varname,"KEYS")) {
lua_getglobal(lua, varname);
ldbLogStackValue(lua,"<value> ");
lua_pop(lua,1);
} else {
ldbLog(sdsnew("No such variable."));
}
}
/* Implements the "print" command (without arguments) of the Lua debugger.
* Prints all the variables in the current stack frame. */
void ldbPrintAll(lua_State *lua) {
lua_Debug ar;
int vars = 0;
if (lua_getstack(lua,0,&ar) != 0) {
const char *name;
int i = 1; /* Variable index. */
while((name = lua_getlocal(lua,&ar,i)) != NULL) {
i++;
if (!strstr(name,"(*temporary)")) {
sds prefix = sdscatprintf(sdsempty(),"<value> %s = ",name);
ldbLogStackValue(lua,prefix);
sdsfree(prefix);
vars++;
}
lua_pop(lua,1);
}
}
if (vars == 0) {
ldbLog(sdsnew("No local variables in the current context."));
}
}
/* Implements the break command to list, add and remove breakpoints. */
void ldbBreak(sds *argv, int argc) {
if (argc == 1) {
if (ldb.bpcount == 0) {
ldbLog(sdsnew("No breakpoints set. Use 'b <line>' to add one."));
return;
} else {
ldbLog(sdscatfmt(sdsempty(),"%i breakpoints set:",ldb.bpcount));
int j;
for (j = 0; j < ldb.bpcount; j++)
ldbLogSourceLine(ldb.bp[j]);
}
} else {
int j;
for (j = 1; j < argc; j++) {
char *arg = argv[j];
long line;
if (!string2l(arg,sdslen(arg),&line)) {
ldbLog(sdscatfmt(sdsempty(),"Invalid argument:'%s'",arg));
} else {
if (line == 0) {
ldb.bpcount = 0;
ldbLog(sdsnew("All breakpoints removed."));
} else if (line > 0) {
if (ldb.bpcount == LDB_BREAKPOINTS_MAX) {
ldbLog(sdsnew("Too many breakpoints set."));
} else if (ldbAddBreakpoint(line)) {
ldbList(line,1);
} else {
ldbLog(sdsnew("Wrong line number."));
}
} else if (line < 0) {
if (ldbDelBreakpoint(-line))
ldbLog(sdsnew("Breakpoint removed."));
else
ldbLog(sdsnew("No breakpoint in the specified line."));
}
}
}
}
}
/* Implements the Lua debugger "eval" command. It just compiles the user
* passed fragment of code and executes it, showing the result left on
* the stack. */
void ldbEval(lua_State *lua, sds *argv, int argc) {
/* Glue the script together if it is composed of multiple arguments. */
sds code = sdsjoinsds(argv+1,argc-1," ",1);
sds expr = sdscatsds(sdsnew("return "),code);
/* Try to compile it as an expression, prepending "return ". */
if (luaL_loadbuffer(lua,expr,sdslen(expr),"@ldb_eval")) {
lua_pop(lua,1);
/* Failed? Try as a statement. */
if (luaL_loadbuffer(lua,code,sdslen(code),"@ldb_eval")) {
ldbLog(sdscatfmt(sdsempty(),"<error> %s",lua_tostring(lua,-1)));
lua_pop(lua,1);
sdsfree(code);
return;
}
}
/* Call it. */
sdsfree(code);
sdsfree(expr);
if (lua_pcall(lua,0,1,0)) {
ldbLog(sdscatfmt(sdsempty(),"<error> %s",lua_tostring(lua,-1)));
lua_pop(lua,1);
return;
}
ldbLogStackValue(lua,"<retval> ");
lua_pop(lua,1);
}
/* Implement the debugger "redis" command. We use a trick in order to make
* the implementation very simple: we just call the Lua redis.call() command
* implementation, with ldb.step enabled, so as a side effect the Redis command
* and its reply are logged. */
void ldbRedis(lua_State *lua, sds *argv, int argc) {
int j, saved_rc = server.lua_replicate_commands;
lua_getglobal(lua,"redis");
lua_pushstring(lua,"call");
lua_gettable(lua,-2); /* Stack: redis, redis.call */
for (j = 1; j < argc; j++)
lua_pushlstring(lua,argv[j],sdslen(argv[j]));
ldb.step = 1; /* Force redis.call() to log. */
server.lua_replicate_commands = 1;
lua_pcall(lua,argc-1,1,0); /* Stack: redis, result */
ldb.step = 0; /* Disable logging. */
server.lua_replicate_commands = saved_rc;
lua_pop(lua,2); /* Discard the result and clean the stack. */
}
/* Implements "trace" command of the Lua debugger. It just prints a backtrace
* querying Lua starting from the current callframe back to the outer one. */
void ldbTrace(lua_State *lua) {
lua_Debug ar;
int level = 0;
while(lua_getstack(lua,level,&ar)) {
lua_getinfo(lua,"Snl",&ar);
if(strstr(ar.short_src,"user_script") != NULL) {
ldbLog(sdscatprintf(sdsempty(),"%s %s:",
(level == 0) ? "In" : "From",
ar.name ? ar.name : "top level"));
ldbLogSourceLine(ar.currentline);
}
level++;
}
if (level == 0) {
ldbLog(sdsnew("<error> Can't retrieve Lua stack."));
}
}
/* Impleemnts the debugger "maxlen" command. It just queries or sets the
* ldb.maxlen variable. */
void ldbMaxlen(sds *argv, int argc) {
if (argc == 2) {
int newval = atoi(argv[1]);
ldb.maxlen_hint_sent = 1; /* User knows about this command. */
if (newval != 0 && newval <= 60) newval = 60;
ldb.maxlen = newval;
}
if (ldb.maxlen) {
ldbLog(sdscatprintf(sdsempty(),"<value> replies are truncated at %d bytes.",(int)ldb.maxlen));
} else {
ldbLog(sdscatprintf(sdsempty(),"<value> replies are unlimited."));
}
}
/* Read debugging commands from client.
* Return C_OK if the debugging session is continuing, otherwise
* C_ERR if the client closed the connection or is timing out. */
int ldbRepl(lua_State *lua) {
sds *argv;
int argc;
/* We continue processing commands until a command that should return
* to the Lua interpreter is found. */
while(1) {
while((argv = ldbReplParseCommand(&argc)) == NULL) {
char buf[1024];
int nread = read(ldb.fd,buf,sizeof(buf));
if (nread <= 0) {
/* Make sure the script runs without user input since the
* client is no longer connected. */
ldb.step = 0;
ldb.bpcount = 0;
return C_ERR;
}
ldb.cbuf = sdscatlen(ldb.cbuf,buf,nread);
}
/* Flush the old buffer. */
sdsfree(ldb.cbuf);
ldb.cbuf = sdsempty();
/* Execute the command. */
if (!strcasecmp(argv[0],"h") || !strcasecmp(argv[0],"help")) {
ldbLog(sdsnew("Redis Lua debugger help:"));
ldbLog(sdsnew("[h]elp Show this help."));
ldbLog(sdsnew("[s]tep Run current line and stop again."));
ldbLog(sdsnew("[n]ext Alias for step."));
ldbLog(sdsnew("[c]continue Run till next breakpoint."));
ldbLog(sdsnew("[l]list List source code around current line."));
ldbLog(sdsnew("[l]list [line] List source code around [line]."));
ldbLog(sdsnew(" line = 0 means: current position."));
ldbLog(sdsnew("[l]list [line] [ctx] In this form [ctx] specifies how many lines"));
ldbLog(sdsnew(" to show before/after [line]."));
ldbLog(sdsnew("[w]hole List all source code. Alias for 'list 1 1000000'."));
ldbLog(sdsnew("[p]rint Show all the local variables."));
ldbLog(sdsnew("[p]rint <var> Show the value of the specified variable."));
ldbLog(sdsnew(" Can also show global vars KEYS and ARGV."));
ldbLog(sdsnew("[b]reak Show all breakpoints."));
ldbLog(sdsnew("[b]reak <line> Add a breakpoint to the specified line."));
ldbLog(sdsnew("[b]reak -<line> Remove breakpoint from the specified line."));
ldbLog(sdsnew("[b]reak 0 Remove all breakpoints."));
ldbLog(sdsnew("[t]race Show a backtrace."));
ldbLog(sdsnew("[e]eval <code> Execute some Lua code (in a different callframe)."));
ldbLog(sdsnew("[r]edis <cmd> Execute a Redis command."));
ldbLog(sdsnew("[m]axlen [len] Trim logged Redis replies and Lua var dumps to len."));
ldbLog(sdsnew(" Specifying zero as <len> means unlimited."));
ldbLog(sdsnew("[a]abort Stop the execution of the script. In sync"));
ldbLog(sdsnew(" mode dataset changes will be retained."));
ldbLog(sdsnew(""));
ldbLog(sdsnew("Debugger functions you can call from Lua scripts:"));
ldbLog(sdsnew("redis.debug() Produce logs in the debugger console."));
ldbLog(sdsnew("redis.breakpoint() Stop execution like if there was a breakpoing."));
ldbLog(sdsnew(" in the next line of code."));
ldbSendLogs();
} else if (!strcasecmp(argv[0],"s") || !strcasecmp(argv[0],"step") ||
!strcasecmp(argv[0],"n") || !strcasecmp(argv[0],"next")) {
ldb.step = 1;
break;
} else if (!strcasecmp(argv[0],"c") || !strcasecmp(argv[0],"continue")){
break;
} else if (!strcasecmp(argv[0],"t") || !strcasecmp(argv[0],"trace")) {
ldbTrace(lua);
ldbSendLogs();
} else if (!strcasecmp(argv[0],"m") || !strcasecmp(argv[0],"maxlen")) {
ldbMaxlen(argv,argc);
ldbSendLogs();
} else if (!strcasecmp(argv[0],"b") || !strcasecmp(argv[0],"break")) {
ldbBreak(argv,argc);
ldbSendLogs();
} else if (!strcasecmp(argv[0],"e") || !strcasecmp(argv[0],"eval")) {
ldbEval(lua,argv,argc);
ldbSendLogs();
} else if (!strcasecmp(argv[0],"a") || !strcasecmp(argv[0],"abort")) {
lua_pushstring(lua, "script aborted for user request");
lua_error(lua);
} else if (argc > 1 &&
(!strcasecmp(argv[0],"r") || !strcasecmp(argv[0],"redis"))) {
ldbRedis(lua,argv,argc);
ldbSendLogs();
} else if ((!strcasecmp(argv[0],"p") || !strcasecmp(argv[0],"print"))) {
if (argc == 2)
ldbPrint(lua,argv[1]);
else
ldbPrintAll(lua);
ldbSendLogs();
} else if (!strcasecmp(argv[0],"l") || !strcasecmp(argv[0],"list")){
int around = ldb.currentline, ctx = 5;
if (argc > 1) {
int num = atoi(argv[1]);
if (num > 0) around = num;
}
if (argc > 2) ctx = atoi(argv[2]);
ldbList(around,ctx);
ldbSendLogs();
} else if (!strcasecmp(argv[0],"w") || !strcasecmp(argv[0],"whole")){
ldbList(1,1000000);
ldbSendLogs();
} else {
ldbLog(sdsnew("<error> Unknown Redis Lua debugger command or "
"wrong number of arguments."));
ldbSendLogs();
}
/* Free the command vector. */
sdsfreesplitres(argv,argc);
}
/* Free the current command argv if we break inside the while loop. */
sdsfreesplitres(argv,argc);
return C_OK;
}
/* This is the core of our Lua debugger, called each time Lua is about
* to start executing a new line. */
void luaLdbLineHook(lua_State *lua, lua_Debug *ar) {
lua_getstack(lua,0,ar);
lua_getinfo(lua,"Sl",ar);
ldb.currentline = ar->currentline;
int bp = ldbIsBreakpoint(ldb.currentline) || ldb.luabp;
int timeout = 0;
/* Events outside our script are not interesting. */
if(strstr(ar->short_src,"user_script") == NULL) return;
/* Check if a timeout occurred. */
if (ar->event == LUA_HOOKCOUNT && ldb.step == 0 && bp == 0) {
mstime_t elapsed = mstime() - server.lua_time_start;
mstime_t timelimit = server.lua_time_limit ?
server.lua_time_limit : 5000;
if (elapsed >= timelimit) {
timeout = 1;
ldb.step = 1;
} else {
return; /* No timeout, ignore the COUNT event. */
}
}
if (ldb.step || bp) {
char *reason = "step over";
if (bp) reason = ldb.luabp ? "redis.breakpoint() called" :
"break point";
else if (timeout) reason = "timeout reached, infinite loop?";
ldb.step = 0;
ldb.luabp = 0;
ldbLog(sdscatprintf(sdsempty(),
"* Stopped at %d, stop reason = %s",
ldb.currentline, reason));
ldbLogSourceLine(ldb.currentline);
ldbSendLogs();
if (ldbRepl(lua) == C_ERR && timeout) {
/* If the client closed the connection and we have a timeout
* connection, let's kill the script otherwise the process
* will remain blocked indefinitely. */
lua_pushstring(lua, "timeout during Lua debugging with client closing connection");
lua_error(lua);
}
server.lua_time_start = mstime();
}
}