fluencelabs/redis
1
0
Fork 0
mirror of https://github.com/fluencelabs/redis synced 2025-03-23 02:50:50 +00:00
Code Issues Projects Releases Wiki Activity

use a struct to retrieve all details for an entry

Browse Source
This commit is contained in:
Pieter Noordhuis 2010-05-29 16:20:01 +02:00
parent dcb9cf4e82
commit a5456b2cb6
1 changed files with 41 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
ziplist.c
View File

@ -51,6 +51,13 @@
#define ZIPLIST_INCR_LENGTH(zl,incr) { \
if (ZIPLIST_LENGTH(zl) < ZIP_BIGLEN) ZIPLIST_LENGTH(zl)+=incr; }
typedef struct zlentry {
unsigned int prevrawlensize, prevrawlen;
unsigned int lensize, len;
unsigned int headersize;
unsigned char encoding;
} zlentry;
/* Return bytes needed to store integer encoded by 'encoding' */
static unsigned int zipEncodingSize(char encoding) {
if (encoding == ZIP_ENC_SHORT) {
@ -192,6 +199,16 @@ static long long zipLoadInteger(unsigned char *p, char encoding) {
return ret;
}
/* Return a struct with all information about an entry. */
static zlentry zipEntry(unsigned char *p) {
zlentry e;
e.prevrawlen = zipDecodeLength(p,&e.prevrawlensize);
e.len = zipDecodeLength(p+e.prevrawlensize,&e.lensize);
e.headersize = e.prevrawlensize+e.lensize;
e.encoding = ZIP_ENCODING(p+e.prevrawlensize);
return e;
}
/* Return the total amount used by an entry (encoded length + payload). */
static unsigned int zipRawEntryLength(unsigned char *p) {
unsigned int prevlensize, lensize, len;
@ -297,9 +314,8 @@ unsigned char *ziplistPush(unsigned char *zl, unsigned char *entry, unsigned int
unsigned char *ziplistPop(unsigned char *zl, sds *target, int where) {
unsigned int curlen = ZIPLIST_BYTES(zl), rawlen;
unsigned int prevrawlensize, prevrawlen, lensize, len, headerlen;
zlentry entry;
int nextdiff = 0;
unsigned char encoding;
unsigned char *p;
long long value;
if (target) *target = NULL;
@ -308,16 +324,13 @@ unsigned char *ziplistPop(unsigned char *zl, sds *target, int where) {
p = (where == ZIPLIST_HEAD) ? ziplistHead(zl) : ziplistTail(zl);
if (*p == ZIP_END) return zl;
prevrawlen = zipDecodeLength(p,&prevrawlensize);
len = zipDecodeLength(p+prevrawlensize,&lensize);
headerlen = prevrawlensize+lensize;
rawlen = headerlen+len;
entry = zipEntry(p);
rawlen = entry.headersize+entry.len;
if (target) {
encoding = ZIP_ENCODING(p+prevrawlensize);
if (encoding == ZIP_ENC_RAW) {
*target = sdsnewlen(p+headerlen,len);
if (entry.encoding == ZIP_ENC_RAW) {
*target = sdsnewlen(p+entry.headersize,entry.len);
} else {
value = zipLoadInteger(p+headerlen,encoding);
value = zipLoadInteger(p+entry.headersize,entry.encoding);
*target = sdscatprintf(sdsempty(), "%lld", value);
}
}
@ -342,7 +355,7 @@ unsigned char *ziplistPop(unsigned char *zl, sds *target, int where) {
ZIPLIST_TAIL_OFFSET(zl) -= rawlen+nextdiff;
} else {
/* Subtract the length of the previous element from the tail offset. */
ZIPLIST_TAIL_OFFSET(zl) -= prevrawlen;
ZIPLIST_TAIL_OFFSET(zl) -= entry.prevrawlen;
}
/* Resize and update length */
@ -372,21 +385,19 @@ unsigned char *ziplistNext(unsigned char *p) {
* to find out whether the string pointer or the integer value was set.
* Return 0 if 'p' points to the end of the zipmap, 1 otherwise. */
unsigned int ziplistGet(unsigned char *p, unsigned char **e, unsigned int *elen, long long *v) {
unsigned int prevrawlensize, lensize, len, headerlen;
zlentry entry;
if (*p == ZIP_END) return 0;
if (e) *e = NULL;
zipDecodeLength(p,&prevrawlensize);
len = zipDecodeLength(p+prevrawlensize,&lensize);
headerlen = prevrawlensize+lensize;
if (ZIP_ENCODING(p+prevrawlensize) == ZIP_ENC_RAW) {
entry = zipEntry(p);
if (entry.encoding == ZIP_ENC_RAW) {
if (e) {
*elen = len;
*e = p+headerlen;
*elen = entry.len;
*e = p+entry.headersize;
}
} else {
if (v) {
*v = zipLoadInteger(p+headerlen,ZIP_ENCODING(p+prevrawlensize));
*v = zipLoadInteger(p+entry.headersize,entry.encoding);
}
}
return 1;
@ -435,27 +446,25 @@ unsigned char *ziplistDelete(unsigned char *zl, unsigned char **p) {
}
/* Compare entry pointer to by 'p' with 'entry'. Return 1 if equal. */
unsigned int ziplistCompare(unsigned char *p, unsigned char *entry, unsigned int elen) {
unsigned int prevrawlensize, lensize, len, headerlen;
char encoding;
long long val, eval;
unsigned int ziplistCompare(unsigned char *p, unsigned char *s, unsigned int slen) {
zlentry entry;
unsigned char sencoding;
long long val, sval;
if (*p == ZIP_END) return 0;
zipDecodeLength(p,&prevrawlensize);
len = zipDecodeLength(p+prevrawlensize,&lensize);
headerlen = prevrawlensize+lensize;
if (ZIP_ENCODING(p+prevrawlensize) == ZIP_ENC_RAW) {
entry = zipEntry(p);
if (entry.encoding == ZIP_ENC_RAW) {
/* Raw compare */
if (len == elen) {
return memcmp(p+headerlen,entry,elen) == 0;
if (entry.len == slen) {
return memcmp(p+entry.headersize,s,slen) == 0;
} else {
return 0;
}
} else {
if (zipTryEncoding(entry,&eval,&encoding)) {
if (zipTryEncoding(s,&sval,&sencoding)) {
/* Do integer compare */
val = zipLoadInteger(p+headerlen,ZIP_ENCODING(p+prevrawlensize));
return val == eval;
val = zipLoadInteger(p+entry.headersize,entry.encoding);
return val == sval;
} else {
/* Ziplist entry is integer encoded, but given entry is not. */
}