Improve RDB type correctness

It's possible large objects could be larger than 'int', so let's
upgrade all size counters to ssize_t.

This also fixes rdbSaveObject serialized bytes calculation.
Since entire serializations of data structures can be large,
so we don't want to limit their calculated size to a 32 bit signed max.

This commit increases object size calculation and
cascades the change back up to serializedlength printing.

Before:
127.0.0.1:6379> debug object hihihi
... encoding:quicklist serializedlength:-2147483559 ...

After:
127.0.0.1:6379> debug object hihihi
... encoding:quicklist serializedlength:2147483737 ...

src/debug.c

@@ -336,10 +336,10 @@ void debugCommand(redisClient *c) {
 
         addReplyStatusFormat(c,
             "Value at:%p refcount:%d "
-            "encoding:%s serializedlength:%lld "
+            "encoding:%s serializedlength:%zu "
             "lru:%d lru_seconds_idle:%llu%s",
             (void*)val, val->refcount,
-            strenc, (long long) rdbSavedObjectLen(val),
+            strenc, rdbSavedObjectLen(val),
             val->lru, estimateObjectIdleTime(val)/1000, extra);
     } else if (!strcasecmp(c->argv[1]->ptr,"sdslen") && c->argc == 3) {
         dictEntry *de;

src/rdb.c

@@ -222,10 +222,10 @@ int rdbTryIntegerEncoding(char *s, size_t len, unsigned char *enc) {
     return rdbEncodeInteger(value,enc);
 }
 
-int rdbSaveLzfBlob(rio *rdb, void *data, size_t compress_len,
+ssize_t rdbSaveLzfBlob(rio *rdb, void *data, size_t compress_len,
-                   size_t original_len) {
+                       size_t original_len) {
     unsigned char byte;
-    int n, nwritten = 0;
+    ssize_t n, nwritten = 0;
 
     /* Data compressed! Let's save it on disk */
     byte = (REDIS_RDB_ENCVAL<<6)|REDIS_RDB_ENC_LZF;
@@ -247,7 +247,7 @@ writeerr:
     return -1;
 }
 
-int rdbSaveLzfStringObject(rio *rdb, unsigned char *s, size_t len) {
+ssize_t rdbSaveLzfStringObject(rio *rdb, unsigned char *s, size_t len) {
     size_t comprlen, outlen;
     void *out;
 
@@ -260,7 +260,7 @@ int rdbSaveLzfStringObject(rio *rdb, unsigned char *s, size_t len) {
         zfree(out);
         return 0;
     }
-    size_t nwritten = rdbSaveLzfBlob(rdb, out, comprlen, len);
+    ssize_t nwritten = rdbSaveLzfBlob(rdb, out, comprlen, len);
     zfree(out);
     return nwritten;
 }
@@ -305,9 +305,9 @@ err:
 
 /* Save a string object as [len][data] on disk. If the object is a string
  * representation of an integer value we try to save it in a special form */
-int rdbSaveRawString(rio *rdb, unsigned char *s, size_t len) {
+ssize_t rdbSaveRawString(rio *rdb, unsigned char *s, size_t len) {
     int enclen;
-    int n, nwritten = 0;
+    ssize_t n, nwritten = 0;
 
     /* Try integer encoding */
     if (len <= 11) {
@@ -338,9 +338,9 @@ int rdbSaveRawString(rio *rdb, unsigned char *s, size_t len) {
 }
 
 /* Save a long long value as either an encoded string or a string. */
-int rdbSaveLongLongAsStringObject(rio *rdb, long long value) {
+ssize_t rdbSaveLongLongAsStringObject(rio *rdb, long long value) {
     unsigned char buf[32];
-    int n, nwritten = 0;
+    ssize_t n, nwritten = 0;
     int enclen = rdbEncodeInteger(value,buf);
     if (enclen > 0) {
         return rdbWriteRaw(rdb,buf,enclen);
@@ -532,8 +532,8 @@ int rdbLoadObjectType(rio *rdb) {
 }
 
 /* Save a Redis object. Returns -1 on error, number of bytes written on success. */
-int rdbSaveObject(rio *rdb, robj *o) {
+ssize_t rdbSaveObject(rio *rdb, robj *o) {
-    int n = 0, nwritten = 0;
+    ssize_t n = 0, nwritten = 0;
 
     if (o->type == REDIS_STRING) {
         /* Save a string value */
@@ -654,8 +654,8 @@ int rdbSaveObject(rio *rdb, robj *o) {
  * the rdbSaveObject() function. Currently we use a trick to get
  * this length with very little changes to the code. In the future
  * we could switch to a faster solution. */
-off_t rdbSavedObjectLen(robj *o) {
+size_t rdbSavedObjectLen(robj *o) {
-    int len = rdbSaveObject(NULL,o);
+    ssize_t len = rdbSaveObject(NULL,o);
     redisAssertWithInfo(NULL,o,len != -1);
     return len;
 }

src/rdb.h

@@ -109,9 +109,8 @@ int rdbSaveBackground(char *filename);
 int rdbSaveToSlavesSockets(void);
 void rdbRemoveTempFile(pid_t childpid);
 int rdbSave(char *filename);
-int rdbSaveObject(rio *rdb, robj *o);
+ssize_t rdbSaveObject(rio *rdb, robj *o);
-off_t rdbSavedObjectLen(robj *o);
+size_t rdbSavedObjectLen(robj *o);
-off_t rdbSavedObjectPages(robj *o);
 robj *rdbLoadObject(int type, rio *rdb);
 void backgroundSaveDoneHandler(int exitcode, int bysignal);
 int rdbSaveKeyValuePair(rio *rdb, robj *key, robj *val, long long expiretime, long long now);