/* Utility macros */
#define ZIPLIST_BYTES(zl) (*((unsigned int*)(zl)))
-#define ZIPLIST_TAIL_OFFSET(zl) (*((zl)+sizeof(unsigned int)))
+#define ZIPLIST_TAIL_OFFSET(zl) (*((unsigned int*)((zl)+sizeof(unsigned int))))
#define ZIPLIST_LENGTH(zl) (*((zl)+2*sizeof(unsigned int)))
#define ZIPLIST_HEADER_SIZE (2*sizeof(unsigned int)+1)
#define ZIPLIST_ENTRY_HEAD(zl) ((zl)+ZIPLIST_HEADER_SIZE)
} zlentry;
/* Return bytes needed to store integer encoded by 'encoding' */
-static unsigned int zipEncodingSize(char encoding) {
+static unsigned int zipEncodingSize(unsigned char encoding) {
if (encoding == ZIP_ENC_SHORT) {
return sizeof(short int);
} else if (encoding == ZIP_ENC_INT) {
return len;
}
+/* Decode the length of the previous element stored at "p". */
+static unsigned int zipPrevDecodeLength(unsigned char *p, unsigned int *lensize) {
+ unsigned int len = *p;
+ if (len < ZIP_BIGLEN) {
+ if (lensize) *lensize = 1;
+ } else {
+ if (lensize) *lensize = 1+sizeof(len);
+ memcpy(&len,p+1,sizeof(len));
+ }
+ return len;
+}
+
+/* Encode the length of the previous entry and write it to "p". Return the
+ * number of bytes needed to encode this length if "p" is NULL. */
+static unsigned int zipPrevEncodeLength(unsigned char *p, unsigned int len) {
+ if (p == NULL) {
+ return (len < ZIP_BIGLEN) ? 1 : sizeof(len)+1;
+ } else {
+ if (len < ZIP_BIGLEN) {
+ p[0] = len;
+ return 1;
+ } else {
+ p[0] = ZIP_BIGLEN;
+ memcpy(p+1,&len,sizeof(len));
+ return 1+sizeof(len);
+ }
+ }
+}
+
/* Return the difference in number of bytes needed to store the new length
* "len" on the entry pointed to by "p". */
static int zipPrevLenByteDiff(unsigned char *p, unsigned int len) {
unsigned int prevlensize;
- zipDecodeLength(p,&prevlensize);
- return zipEncodeLength(NULL,ZIP_ENC_RAW,len)-prevlensize;
+ zipPrevDecodeLength(p,&prevlensize);
+ return zipPrevEncodeLength(NULL,len)-prevlensize;
}
/* Check if string pointed to by 'entry' can be encoded as an integer.
* Stores the integer value in 'v' and its encoding in 'encoding'.
* Warning: this function requires a NULL-terminated string! */
-static int zipTryEncoding(unsigned char *entry, long long *v, char *encoding) {
+static int zipTryEncoding(unsigned char *entry, long long *v, unsigned char *encoding) {
long long value;
char *eptr;
}
/* Store integer 'value' at 'p', encoded as 'encoding' */
-static void zipSaveInteger(unsigned char *p, long long value, char encoding) {
+static void zipSaveInteger(unsigned char *p, long long value, unsigned char encoding) {
short int s;
int i;
long long l;
}
/* Read integer encoded as 'encoding' from 'p' */
-static long long zipLoadInteger(unsigned char *p, char encoding) {
+static long long zipLoadInteger(unsigned char *p, unsigned char encoding) {
short int s;
int i;
long long l, 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.prevrawlen = zipPrevDecodeLength(p,&e.prevrawlensize);
e.len = zipDecodeLength(p+e.prevrawlensize,&e.lensize);
e.headersize = e.prevrawlensize+e.lensize;
e.encoding = ZIP_ENCODING(p+e.prevrawlensize);
}
/* Delete "num" entries, starting at "p". Returns pointer to the ziplist. */
-static unsigned char *__ziplistDelete(unsigned char *zl, unsigned char *p, int num) {
+static unsigned char *__ziplistDelete(unsigned char *zl, unsigned char *p, unsigned int num) {
unsigned int i, totlen, deleted = 0;
int nextdiff = 0;
zlentry first = zipEntry(p);
* prevlen. Note that we can always store this length because
* it was previously stored by an entry that is being deleted. */
nextdiff = zipPrevLenByteDiff(p,first.prevrawlen);
- zipEncodeLength(p-nextdiff,ZIP_ENC_RAW,first.prevrawlen);
+ zipPrevEncodeLength(p-nextdiff,first.prevrawlen);
/* Update offset for tail */
ZIPLIST_TAIL_OFFSET(zl) -= totlen+nextdiff;
unsigned int curlen = ZIPLIST_BYTES(zl), reqlen, prevlen = 0;
unsigned int offset, nextdiff = 0;
unsigned char *tail;
- char encoding = ZIP_ENC_RAW;
+ unsigned char encoding = ZIP_ENC_RAW;
long long value;
zlentry entry;
/* We need space for both the length of the previous entry and
* the length of the payload. */
- reqlen += zipEncodeLength(NULL,ZIP_ENC_RAW,prevlen);
+ reqlen += zipPrevEncodeLength(NULL,prevlen);
reqlen += zipEncodeLength(NULL,encoding,slen);
/* When the insert position is not equal to the tail, we need to
* make sure that the next entry can hold this entry's length in
* its prevlen field. */
- nextdiff = p[0] != ZIP_END ? zipPrevLenByteDiff(p,reqlen) : 0;
+ nextdiff = (p[0] != ZIP_END) ? zipPrevLenByteDiff(p,reqlen) : 0;
/* Store offset because a realloc may change the address of zl. */
offset = p-zl;
/* Subtract one because of the ZIP_END bytes */
memmove(p+reqlen,p-nextdiff,curlen-offset-1+nextdiff);
/* Encode this entry's raw length in the next entry. */
- zipEncodeLength(p+reqlen,ZIP_ENC_RAW,reqlen);
+ zipPrevEncodeLength(p+reqlen,reqlen);
/* Update offset for tail */
ZIPLIST_TAIL_OFFSET(zl) += reqlen+nextdiff;
} else {
}
/* Write the entry */
- p += zipEncodeLength(p,ZIP_ENC_RAW,prevlen);
+ p += zipPrevEncodeLength(p,prevlen);
p += zipEncodeLength(p,encoding,slen);
if (encoding != ZIP_ENC_RAW) {
zipSaveInteger(p,value,encoding);
return zl;
}
-/* Returns an offset to use for iterating with ziplistNext. */
-unsigned char *ziplistIndex(unsigned char *zl, unsigned int index) {
- unsigned char *p = zl+ZIPLIST_HEADER_SIZE;
- unsigned int i = 0;
- for (; i < index; i++) {
- if (*p == ZIP_END) break;
- p += zipRawEntryLength(p);
+/* Returns an offset to use for iterating with ziplistNext. When the given
+ * index is negative, the list is traversed back to front. When the list
+ * doesn't contain an element at the provided index, NULL is returned. */
+unsigned char *ziplistIndex(unsigned char *zl, int index) {
+ unsigned char *p;
+ zlentry entry;
+ if (index < 0) {
+ index = (-index)-1;
+ p = ZIPLIST_ENTRY_TAIL(zl);
+ if (p[0] != ZIP_END) {
+ entry = zipEntry(p);
+ while (entry.prevrawlen > 0 && index--) {
+ p -= entry.prevrawlen;
+ entry = zipEntry(p);
+ }
+ }
+ } else {
+ p = ZIPLIST_ENTRY_HEAD(zl);
+ while (p[0] != ZIP_END && index--) {
+ p += zipRawEntryLength(p);
+ }
}
- return p;
+ return (p[0] == ZIP_END || index > 0) ? NULL : p;
}
/* Return pointer to next entry in ziplist. */
-unsigned char *ziplistNext(unsigned char *p) {
- return *p == ZIP_END ? p : p+zipRawEntryLength(p);
+unsigned char *ziplistNext(unsigned char *zl, unsigned char *p) {
+ ((void) zl);
+
+ /* "p" could be equal to ZIP_END, caused by ziplistDelete,
+ * and we should return NULL. Otherwise, we should return NULL
+ * when the *next* element is ZIP_END (there is no next entry). */
+ if (p[0] == ZIP_END) {
+ return NULL;
+ } else {
+ p = p+zipRawEntryLength(p);
+ return (p[0] == ZIP_END) ? NULL : p;
+ }
+}
+
+/* Return pointer to previous entry in ziplist. */
+unsigned char *ziplistPrev(unsigned char *zl, unsigned char *p) {
+ zlentry entry;
+
+ /* Iterating backwards from ZIP_END should return the tail. When "p" is
+ * equal to the first element of the list, we're already at the head,
+ * and should return NULL. */
+ if (p[0] == ZIP_END) {
+ p = ZIPLIST_ENTRY_TAIL(zl);
+ return (p[0] == ZIP_END) ? NULL : p;
+ } else if (p == ZIPLIST_ENTRY_HEAD(zl)) {
+ return NULL;
+ } else {
+ entry = zipEntry(p);
+ return p-entry.prevrawlen;
+ }
}
/* Get entry pointer to by 'p' and store in either 'e' or 'v' depending
* Return 0 if 'p' points to the end of the zipmap, 1 otherwise. */
unsigned int ziplistGet(unsigned char *p, unsigned char **sstr, unsigned int *slen, long long *sval) {
zlentry entry;
- if (*p == ZIP_END) return 0;
+ if (p == NULL || p[0] == ZIP_END) return 0;
if (sstr) *sstr = NULL;
entry = zipEntry(p);
return 1;
}
-/* Delete a range of entries from the ziplist. */
-unsigned char *ziplistDeleteRange(unsigned char *zl, unsigned int index, unsigned int num) {
- unsigned char *p = ziplistIndex(zl,index);
- return __ziplistDelete(zl,p,num);
+/* Insert an entry at "p". */
+unsigned char *ziplistInsert(unsigned char *zl, unsigned char *p, unsigned char *s, unsigned int slen) {
+ return __ziplistInsert(zl,p,s,slen);
}
/* Delete a single entry from the ziplist, pointed to by *p.
zl = __ziplistDelete(zl,*p,1);
/* Store pointer to current element in p, because ziplistDelete will
- * do a realloc which might result in a different "zl"-pointer. */
+ * do a realloc which might result in a different "zl"-pointer.
+ * When the delete direction is back to front, we might delete the last
+ * entry and end up with "p" pointing to ZIP_END, so check this. */
*p = zl+offset;
return zl;
}
+/* Delete a range of entries from the ziplist. */
+unsigned char *ziplistDeleteRange(unsigned char *zl, unsigned int index, unsigned int num) {
+ unsigned char *p = ziplistIndex(zl,index);
+ return (p == NULL) ? zl : __ziplistDelete(zl,p,num);
+}
+
/* Compare entry pointer to by 'p' with 'entry'. Return 1 if equal. */
unsigned int ziplistCompare(unsigned char *p, unsigned char *sstr, unsigned int slen) {
zlentry entry;
unsigned char sencoding;
- long long val, sval;
- if (*p == ZIP_END) return 0;
+ long long zval, sval;
+ if (p[0] == ZIP_END) return 0;
entry = zipEntry(p);
if (entry.encoding == ZIP_ENC_RAW) {
/* Try to compare encoded values */
if (zipTryEncoding(sstr,&sval,&sencoding)) {
if (entry.encoding == sencoding) {
- val = zipLoadInteger(p+entry.headersize,entry.encoding);
- return val == sval;
+ zval = zipLoadInteger(p+entry.headersize,entry.encoding);
+ return zval == sval;
}
}
}
char buf[32];
sprintf(buf, "100");
- zl = ziplistPush(zl, buf, strlen(buf), ZIPLIST_TAIL);
+ zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_TAIL);
sprintf(buf, "128000");
- zl = ziplistPush(zl, buf, strlen(buf), ZIPLIST_TAIL);
+ zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_TAIL);
sprintf(buf, "-100");
- zl = ziplistPush(zl, buf, strlen(buf), ZIPLIST_HEAD);
+ zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_HEAD);
sprintf(buf, "4294967296");
- zl = ziplistPush(zl, buf, strlen(buf), ZIPLIST_HEAD);
+ zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_HEAD);
sprintf(buf, "non integer");
- zl = ziplistPush(zl, buf, strlen(buf), ZIPLIST_TAIL);
+ zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_TAIL);
sprintf(buf, "much much longer non integer");
- zl = ziplistPush(zl, buf, strlen(buf), ZIPLIST_TAIL);
+ zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_TAIL);
return zl;
}
int main(int argc, char **argv) {
- unsigned char *zl, *p, *q, *entry;
+ unsigned char *zl, *p;
+ unsigned char *entry;
unsigned int elen;
long long value;
sds s;
printf("Pop tail: %s (length %ld)\n", s, sdslen(s));
ziplistRepr(zl);
+ printf("Get element at index 3:\n");
+ {
+ zl = createList();
+ p = ziplistIndex(zl, 3);
+ if (!ziplistGet(p, &entry, &elen, &value)) {
+ printf("ERROR: Could not access index 3\n");
+ return 1;
+ }
+ if (entry) {
+ fwrite(entry,elen,1,stdout);
+ printf("\n");
+ } else {
+ printf("%lld\n", value);
+ }
+ printf("\n");
+ }
+
+ printf("Get element at index 4 (out of range):\n");
+ {
+ zl = createList();
+ p = ziplistIndex(zl, 4);
+ if (p == NULL) {
+ printf("No entry\n");
+ } else {
+ printf("ERROR: Out of range index should return NULL, returned offset: %ld\n", p-zl);
+ return 1;
+ }
+ printf("\n");
+ }
+
+ printf("Get element at index -1 (last element):\n");
+ {
+ zl = createList();
+ p = ziplistIndex(zl, -1);
+ if (!ziplistGet(p, &entry, &elen, &value)) {
+ printf("ERROR: Could not access index -1\n");
+ return 1;
+ }
+ if (entry) {
+ fwrite(entry,elen,1,stdout);
+ printf("\n");
+ } else {
+ printf("%lld\n", value);
+ }
+ printf("\n");
+ }
+
+ printf("Get element at index -4 (first element):\n");
+ {
+ zl = createList();
+ p = ziplistIndex(zl, -4);
+ if (!ziplistGet(p, &entry, &elen, &value)) {
+ printf("ERROR: Could not access index -4\n");
+ return 1;
+ }
+ if (entry) {
+ fwrite(entry,elen,1,stdout);
+ printf("\n");
+ } else {
+ printf("%lld\n", value);
+ }
+ printf("\n");
+ }
+
+ printf("Get element at index -5 (reverse out of range):\n");
+ {
+ zl = createList();
+ p = ziplistIndex(zl, -5);
+ if (p == NULL) {
+ printf("No entry\n");
+ } else {
+ printf("ERROR: Out of range index should return NULL, returned offset: %ld\n", p-zl);
+ return 1;
+ }
+ printf("\n");
+ }
+
printf("Iterate list from 0 to end:\n");
{
zl = createList();
} else {
printf("%lld", value);
}
- p = ziplistNext(p);
+ p = ziplistNext(zl,p);
printf("\n");
}
printf("\n");
} else {
printf("%lld", value);
}
- p = ziplistNext(p);
+ p = ziplistNext(zl,p);
printf("\n");
}
printf("\n");
} else {
printf("%lld", value);
}
- p = ziplistNext(p);
+ p = ziplistNext(zl,p);
printf("\n");
}
printf("\n");
printf("\n");
}
+ printf("Iterate from back to front:\n");
+ {
+ zl = createList();
+ p = ziplistIndex(zl, -1);
+ while (ziplistGet(p, &entry, &elen, &value)) {
+ printf("Entry: ");
+ if (entry) {
+ fwrite(entry,elen,1,stdout);
+ } else {
+ printf("%lld", value);
+ }
+ p = ziplistPrev(zl,p);
+ printf("\n");
+ }
+ printf("\n");
+ }
+
+ printf("Iterate from back to front, deleting all items:\n");
+ {
+ zl = createList();
+ p = ziplistIndex(zl, -1);
+ while (ziplistGet(p, &entry, &elen, &value)) {
+ printf("Entry: ");
+ if (entry) {
+ fwrite(entry,elen,1,stdout);
+ } else {
+ printf("%lld", value);
+ }
+ zl = ziplistDelete(zl,&p);
+ p = ziplistPrev(zl,p);
+ printf("\n");
+ }
+ printf("\n");
+ }
+
printf("Delete inclusive range 0,0:\n");
{
zl = createList();
printf("Delete foo while iterating:\n");
{
zl = createList();
- p = ziplistIndex(zl, 0);
- while (ziplistGet(p, &entry, &elen, &value)) {
- if (entry && strncmp("foo", entry, elen) == 0) {
+ p = ziplistIndex(zl,0);
+ while (ziplistGet(p,&entry,&elen,&value)) {
+ if (entry && strncmp("foo",(char*)entry,elen) == 0) {
printf("Delete foo\n");
- zl = ziplistDelete(zl, &p);
+ zl = ziplistDelete(zl,&p);
} else {
printf("Entry: ");
if (entry) {
fwrite(entry,elen,1,stdout);
} else {
- printf("%lld", value);
+ printf("%lld",value);
}
- p = ziplistNext(p);
+ p = ziplistNext(zl,p);
printf("\n");
}
}
ziplistRepr(zl);
}
+ printf("Create long list and check indices:\n");
+ {
+ zl = ziplistNew();
+ char buf[32];
+ int i,len;
+ for (i = 0; i < 1000; i++) {
+ len = sprintf(buf,"%d",i);
+ zl = ziplistPush(zl,(unsigned char*)buf,len,ZIPLIST_TAIL);
+ }
+ for (i = 0; i < 1000; i++) {
+ p = ziplistIndex(zl,i);
+ assert(ziplistGet(p,NULL,NULL,&value));
+ assert(i == value);
+
+ p = ziplistIndex(zl,-i-1);
+ assert(ziplistGet(p,NULL,NULL,&value));
+ assert(999-i == value);
+ }
+ printf("SUCCESS\n\n");
+ }
+
printf("Compare strings with ziplist entries:\n");
{
zl = createList();
- p = ziplistIndex(zl, 0);
- if (!ziplistCompare(p,"hello",5)) {
+ p = ziplistIndex(zl,0);
+ if (!ziplistCompare(p,(unsigned char*)"hello",5)) {
printf("ERROR: not \"hello\"\n");
- return;
+ return 1;
}
- if (ziplistCompare(p,"hella",5)) {
+ if (ziplistCompare(p,(unsigned char*)"hella",5)) {
printf("ERROR: \"hella\"\n");
- return;
+ return 1;
}
- p = ziplistIndex(zl, 3);
- if (!ziplistCompare(p,"1024",4)) {
+ p = ziplistIndex(zl,3);
+ if (!ziplistCompare(p,(unsigned char*)"1024",4)) {
printf("ERROR: not \"1024\"\n");
- return;
+ return 1;
}
- if (ziplistCompare(p,"1025",4)) {
+ if (ziplistCompare(p,(unsigned char*)"1025",4)) {
printf("ERROR: \"1025\"\n");
- return;
+ return 1;
}
printf("SUCCESS\n");
}
projects / redis.git / blobdiff