#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <stdint.h>
#include <assert.h>
#include <limits.h>
#include "zmalloc.h"
#include "sds.h"
#include "ziplist.h"
+/* Important note: the ZIP_END value is used to depict the end of the
+ * ziplist structure. When a pointer contains an entry, the first couple
+ * of bytes contain the encoded length of the previous entry. This length
+ * is encoded as ZIP_ENC_RAW length, so the first two bits will contain 00
+ * and the byte will therefore never have a value of 255. */
#define ZIP_END 255
+#define ZIP_BIGLEN 254
/* Entry encoding */
#define ZIP_ENC_RAW 0
-#define ZIP_ENC_SHORT 1
-#define ZIP_ENC_INT 2
-#define ZIP_ENC_LLONG 3
+#define ZIP_ENC_INT16 1
+#define ZIP_ENC_INT32 2
+#define ZIP_ENC_INT64 3
#define ZIP_ENCODING(p) ((p)[0] >> 6)
/* Length encoding for raw entries */
#define ZIP_LEN_UINT32 2
/* Utility macros */
-#define ZIPLIST_BYTES(zl) (*((unsigned int*)(zl)))
-#define ZIPLIST_LENGTH(zl) (*((zl)+sizeof(unsigned int)))
-#define ZIPLIST_HEADER_SIZE (sizeof(unsigned int)+1)
+#define ZIPLIST_BYTES(zl) (*((uint32_t*)(zl)))
+#define ZIPLIST_TAIL_OFFSET(zl) (*((uint32_t*)((zl)+sizeof(uint32_t))))
+#define ZIPLIST_LENGTH(zl) (*((uint16_t*)((zl)+sizeof(uint32_t)*2)))
+#define ZIPLIST_HEADER_SIZE (sizeof(uint32_t)*2+sizeof(uint16_t))
+#define ZIPLIST_ENTRY_HEAD(zl) ((zl)+ZIPLIST_HEADER_SIZE)
+#define ZIPLIST_ENTRY_TAIL(zl) ((zl)+ZIPLIST_TAIL_OFFSET(zl))
+#define ZIPLIST_ENTRY_END(zl) ((zl)+ZIPLIST_BYTES(zl)-1)
+
+/* We know a positive increment can only be 1 because entries can only be
+ * pushed one at a time. */
#define ZIPLIST_INCR_LENGTH(zl,incr) { \
- if (ZIPLIST_LENGTH(zl) < (ZIP_END-1)) ZIPLIST_LENGTH(zl)+=incr; }
+ if (ZIPLIST_LENGTH(zl) < UINT16_MAX) ZIPLIST_LENGTH(zl)+=incr; }
+
+typedef struct zlentry {
+ unsigned int prevrawlensize, prevrawlen;
+ unsigned int lensize, len;
+ unsigned int headersize;
+ unsigned char encoding;
+ unsigned char *p;
+} zlentry;
/* Return bytes needed to store integer encoded by 'encoding' */
-static unsigned int zipEncodingSize(char encoding) {
- if (encoding == ZIP_ENC_SHORT) {
- return sizeof(short int);
- } else if (encoding == ZIP_ENC_INT) {
- return sizeof(int);
- } else if (encoding == ZIP_ENC_LLONG) {
- return sizeof(long long);
+static unsigned int zipEncodingSize(unsigned char encoding) {
+ if (encoding == ZIP_ENC_INT16) {
+ return sizeof(int16_t);
+ } else if (encoding == ZIP_ENC_INT32) {
+ return sizeof(int32_t);
+ } else if (encoding == ZIP_ENC_INT64) {
+ return sizeof(int64_t);
}
assert(NULL);
}
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;
+ 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;
if (entry[0] == '-' || (entry[0] >= '0' && entry[0] <= '9')) {
- value = strtoll(entry,&eptr,10);
+ value = strtoll((char*)entry,&eptr,10);
if (eptr[0] != '\0') return 0;
- if (value >= SHRT_MIN && value <= SHRT_MAX) {
- *encoding = ZIP_ENC_SHORT;
- } else if (value >= INT_MIN && value <= INT_MAX) {
- *encoding = ZIP_ENC_INT;
+ if (value >= INT16_MIN && value <= INT16_MAX) {
+ *encoding = ZIP_ENC_INT16;
+ } else if (value >= INT32_MIN && value <= INT32_MAX) {
+ *encoding = ZIP_ENC_INT32;
} else {
- *encoding = ZIP_ENC_LLONG;
+ *encoding = ZIP_ENC_INT64;
}
*v = value;
return 1;
}
/* Store integer 'value' at 'p', encoded as 'encoding' */
-static void zipSaveInteger(unsigned char *p, long long value, char encoding) {
- short int s;
- int i;
- long long l;
- if (encoding == ZIP_ENC_SHORT) {
- s = value;
- memcpy(p,&s,sizeof(s));
- } else if (encoding == ZIP_ENC_INT) {
- i = value;
- memcpy(p,&i,sizeof(i));
- } else if (encoding == ZIP_ENC_LLONG) {
- l = value;
- memcpy(p,&l,sizeof(l));
+static void zipSaveInteger(unsigned char *p, int64_t value, unsigned char encoding) {
+ int16_t i16;
+ int32_t i32;
+ int64_t i64;
+ if (encoding == ZIP_ENC_INT16) {
+ i16 = value;
+ memcpy(p,&i16,sizeof(i16));
+ } else if (encoding == ZIP_ENC_INT32) {
+ i32 = value;
+ memcpy(p,&i32,sizeof(i32));
+ } else if (encoding == ZIP_ENC_INT64) {
+ i64 = value;
+ memcpy(p,&i64,sizeof(i64));
} else {
assert(NULL);
}
}
/* Read integer encoded as 'encoding' from 'p' */
-static long long zipLoadInteger(unsigned char *p, char encoding) {
- short int s;
- int i;
- long long l, ret;
- if (encoding == ZIP_ENC_SHORT) {
- memcpy(&s,p,sizeof(s));
- ret = s;
- } else if (encoding == ZIP_ENC_INT) {
- memcpy(&i,p,sizeof(i));
- ret = i;
- } else if (encoding == ZIP_ENC_LLONG) {
- memcpy(&l,p,sizeof(l));
- ret = l;
+static int64_t zipLoadInteger(unsigned char *p, unsigned char encoding) {
+ int16_t i16;
+ int32_t i32;
+ int64_t i64, ret;
+ if (encoding == ZIP_ENC_INT16) {
+ memcpy(&i16,p,sizeof(i16));
+ ret = i16;
+ } else if (encoding == ZIP_ENC_INT32) {
+ memcpy(&i32,p,sizeof(i32));
+ ret = i32;
+ } else if (encoding == ZIP_ENC_INT64) {
+ memcpy(&i64,p,sizeof(i64));
+ ret = i64;
} else {
assert(NULL);
}
return ret;
}
-/* Return the total amount used by an entry (encoded length + payload). */
+/* Return a struct with all information about an entry. */
+static zlentry zipEntry(unsigned char *p) {
+ zlentry e;
+ 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);
+ e.p = p;
+ return e;
+}
+
+/* Return the total number of bytes used by the entry at "p". */
static unsigned int zipRawEntryLength(unsigned char *p) {
- unsigned int lensize, len;
- len = zipDecodeLength(p, &lensize);
- return lensize + len;
+ zlentry e = zipEntry(p);
+ return e.headersize + e.len;
}
/* Create a new empty ziplist. */
unsigned int bytes = ZIPLIST_HEADER_SIZE+1;
unsigned char *zl = zmalloc(bytes);
ZIPLIST_BYTES(zl) = bytes;
+ ZIPLIST_TAIL_OFFSET(zl) = ZIPLIST_HEADER_SIZE;
ZIPLIST_LENGTH(zl) = 0;
zl[bytes-1] = ZIP_END;
return zl;
return zl;
}
-static unsigned char *ziplistHead(unsigned char *zl) {
- return zl+ZIPLIST_HEADER_SIZE;
-}
-
-static unsigned char *ziplistTail(unsigned char *zl) {
- unsigned char *p, *q;
- p = q = ziplistHead(zl);
- while (*p != ZIP_END) {
- q = p;
+/* Delete "num" entries, starting at "p". Returns pointer to the ziplist. */
+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);
+ for (i = 0; p[0] != ZIP_END && i < num; i++) {
p += zipRawEntryLength(p);
+ deleted++;
+ }
+
+ totlen = p-first.p;
+ if (totlen > 0) {
+ if (p[0] != ZIP_END) {
+ /* Tricky: storing the prevlen in this entry might reduce or
+ * increase the number of bytes needed, compared to the current
+ * 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);
+ zipPrevEncodeLength(p-nextdiff,first.prevrawlen);
+
+ /* Update offset for tail */
+ ZIPLIST_TAIL_OFFSET(zl) -= totlen+nextdiff;
+
+ /* Move tail to the front of the ziplist */
+ memmove(first.p,p-nextdiff,ZIPLIST_BYTES(zl)-(p-zl)-1+nextdiff);
+ } else {
+ /* The entire tail was deleted. No need to move memory. */
+ ZIPLIST_TAIL_OFFSET(zl) = (first.p-zl)-first.prevrawlen;
+ }
+
+ /* Resize and update length */
+ zl = ziplistResize(zl, ZIPLIST_BYTES(zl)-totlen+nextdiff);
+ ZIPLIST_INCR_LENGTH(zl,-deleted);
}
- return q;
+ return zl;
}
-unsigned char *ziplistPush(unsigned char *zl, unsigned char *entry, unsigned int elen, int where) {
- unsigned int curlen = ZIPLIST_BYTES(zl), reqlen;
- unsigned char *p;
- char encoding = ZIP_ENC_RAW;
+/* Insert item at "p". */
+static unsigned char *__ziplistInsert(unsigned char *zl, unsigned char *p, unsigned char *s, unsigned int slen) {
+ unsigned int curlen = ZIPLIST_BYTES(zl), reqlen, prevlen = 0;
+ unsigned int offset, nextdiff = 0;
+ unsigned char *tail;
+ unsigned char encoding = ZIP_ENC_RAW;
long long value;
+ zlentry entry;
+
+ /* Find out prevlen for the entry that is inserted. */
+ if (p[0] != ZIP_END) {
+ entry = zipEntry(p);
+ prevlen = entry.prevrawlen;
+ } else {
+ tail = ZIPLIST_ENTRY_TAIL(zl);
+ if (tail[0] != ZIP_END) {
+ prevlen = zipRawEntryLength(tail);
+ }
+ }
/* See if the entry can be encoded */
- if (zipTryEncoding(entry,&value,&encoding)) {
+ if (zipTryEncoding(s,&value,&encoding)) {
reqlen = zipEncodingSize(encoding);
} else {
- reqlen = elen;
+ reqlen = slen;
}
- reqlen += zipEncodeLength(NULL,encoding,elen);
- /* Resize the ziplist and move if needed */
- zl = ziplistResize(zl,curlen+reqlen);
- if (where == ZIPLIST_HEAD) {
- p = zl+ZIPLIST_HEADER_SIZE;
- if (*p != ZIP_END) {
- /* Subtract one because of the ZIP_END bytes */
- memmove(p+reqlen,p,curlen-ZIPLIST_HEADER_SIZE-1);
- }
+ /* We need space for both the length of the previous entry and
+ * the length of the payload. */
+ 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;
+
+ /* Store offset because a realloc may change the address of zl. */
+ offset = p-zl;
+ zl = ziplistResize(zl,curlen+reqlen+nextdiff);
+ p = zl+offset;
+
+ /* Apply memory move when necessary and update tail offset. */
+ if (p[0] != ZIP_END) {
+ /* 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. */
+ zipPrevEncodeLength(p+reqlen,reqlen);
+ /* Update offset for tail */
+ ZIPLIST_TAIL_OFFSET(zl) += reqlen+nextdiff;
} else {
- p = zl+curlen-1;
+ /* This element will be the new tail. */
+ ZIPLIST_TAIL_OFFSET(zl) = p-zl;
}
/* Write the entry */
- p += zipEncodeLength(p,encoding,elen);
+ p += zipPrevEncodeLength(p,prevlen);
+ p += zipEncodeLength(p,encoding,slen);
if (encoding != ZIP_ENC_RAW) {
zipSaveInteger(p,value,encoding);
} else {
- memcpy(p,entry,elen);
+ memcpy(p,s,slen);
}
ZIPLIST_INCR_LENGTH(zl,1);
return zl;
}
+unsigned char *ziplistPush(unsigned char *zl, unsigned char *s, unsigned int slen, int where) {
+ unsigned char *p;
+ p = (where == ZIPLIST_HEAD) ? ZIPLIST_ENTRY_HEAD(zl) : ZIPLIST_ENTRY_END(zl);
+ return __ziplistInsert(zl,p,s,slen);
+}
+
unsigned char *ziplistPop(unsigned char *zl, sds *target, int where) {
- unsigned int curlen = ZIPLIST_BYTES(zl), rawlen;
- unsigned int len, lensize;
+ zlentry entry;
unsigned char *p;
long long value;
if (target) *target = NULL;
/* Get pointer to element to remove */
- p = (where == ZIPLIST_HEAD) ? ziplistHead(zl) : ziplistTail(zl);
+ p = (where == ZIPLIST_HEAD) ? ZIPLIST_ENTRY_HEAD(zl) : ZIPLIST_ENTRY_TAIL(zl);
if (*p == ZIP_END) return zl;
- len = zipDecodeLength(p,&lensize);
+
+ entry = zipEntry(p);
if (target) {
- if (ZIP_ENCODING(p) == ZIP_ENC_RAW) {
- *target = sdsnewlen(p+lensize,len);
+ if (entry.encoding == ZIP_ENC_RAW) {
+ *target = sdsnewlen(p+entry.headersize,entry.len);
} else {
- value = zipLoadInteger(p+lensize,ZIP_ENCODING(p));
+ value = zipLoadInteger(p+entry.headersize,entry.encoding);
*target = sdscatprintf(sdsempty(), "%lld", value);
}
}
- /* Move list to front when popping from the head */
- rawlen = lensize+len;
- if (where == ZIPLIST_HEAD) {
- memmove(p,p+rawlen,curlen-ZIPLIST_HEADER_SIZE-len);
- }
-
- /* Resize and update length */
- zl = ziplistResize(zl,curlen-rawlen);
- ZIPLIST_INCR_LENGTH(zl,-1);
+ zl = __ziplistDelete(zl,p,1);
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
* on the encoding of the entry. 'e' is always set to NULL to be able
* 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 len, lensize;
- if (*p == ZIP_END) return 0;
- if (e) *e = NULL;
- len = zipDecodeLength(p,&lensize);
- if (ZIP_ENCODING(p) == ZIP_ENC_RAW) {
- if (e) {
- *elen = len;
- *e = p+lensize;
+unsigned int ziplistGet(unsigned char *p, unsigned char **sstr, unsigned int *slen, long long *sval) {
+ zlentry entry;
+ if (p == NULL || p[0] == ZIP_END) return 0;
+ if (sstr) *sstr = NULL;
+
+ entry = zipEntry(p);
+ if (entry.encoding == ZIP_ENC_RAW) {
+ if (sstr) {
+ *slen = entry.len;
+ *sstr = p+entry.headersize;
}
} else {
- if (v) {
- *v = zipLoadInteger(p+lensize,ZIP_ENCODING(p));
+ if (sval) {
+ *sval = zipLoadInteger(p+entry.headersize,entry.encoding);
}
}
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, *first = ziplistIndex(zl, index);
- unsigned int i, deleted = 0, totlen, newlen;
- for (p = first, i = 0; *p != ZIP_END && i < num; i++) {
- p += zipRawEntryLength(p);
- deleted++;
- }
-
- totlen = p-first;
- if (totlen > 0) {
- /* Move current tail to the new tail when there *is* a tail */
- if (*p != ZIP_END) memmove(first,p,ZIPLIST_BYTES(zl)-(p-zl)-1);
-
- /* Resize and update length */
- zl = ziplistResize(zl, ZIPLIST_BYTES(zl)-totlen);
- ZIPLIST_INCR_LENGTH(zl,-deleted);
- }
- return zl;
+/* 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.
* Also update *p in place, to be able to iterate over the
* ziplist, while deleting entries. */
unsigned char *ziplistDelete(unsigned char *zl, unsigned char **p) {
- unsigned int offset = *p-zl, tail, len;
- len = zipRawEntryLength(*p);
- tail = ZIPLIST_BYTES(zl)-offset-len-1;
-
- /* Move current tail to the new tail when there *is* a tail */
- if (tail > 0) memmove(*p,*p+len,tail);
+ unsigned int offset = *p-zl;
+ zl = __ziplistDelete(zl,*p,1);
- /* Resize and update length */
- zl = ziplistResize(zl, ZIPLIST_BYTES(zl)-len);
- ZIPLIST_INCR_LENGTH(zl,-1);
-
- /* Store new pointer to current element in p.
- * This needs to be done because zl can change on realloc. */
+ /* Store pointer to current element in p, because ziplistDelete will
+ * 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 zval, sval;
+ if (p[0] == ZIP_END) return 0;
+
+ entry = zipEntry(p);
+ if (entry.encoding == ZIP_ENC_RAW) {
+ /* Raw compare */
+ if (entry.len == slen) {
+ return memcmp(p+entry.headersize,sstr,slen) == 0;
+ } else {
+ return 0;
+ }
+ } else {
+ /* Try to compare encoded values */
+ if (zipTryEncoding(sstr,&sval,&sencoding)) {
+ if (entry.encoding == sencoding) {
+ zval = zipLoadInteger(p+entry.headersize,entry.encoding);
+ return zval == sval;
+ }
+ }
+ }
+ return 0;
+}
+
+/* Return length of ziplist. */
+unsigned int ziplistLen(unsigned char *zl) {
+ unsigned int len = 0;
+ if (ZIPLIST_LENGTH(zl) < UINT16_MAX) {
+ len = ZIPLIST_LENGTH(zl);
+ } else {
+ unsigned char *p = zl+ZIPLIST_HEADER_SIZE;
+ while (*p != ZIP_END) {
+ p += zipRawEntryLength(p);
+ len++;
+ }
+
+ /* Re-store length if small enough */
+ if (len < UINT16_MAX) ZIPLIST_LENGTH(zl) = len;
+ }
+ return len;
+}
+
+/* Return size in bytes of ziplist. */
+unsigned int ziplistSize(unsigned char *zl) {
+ return ZIPLIST_BYTES(zl);
+}
+
void ziplistRepr(unsigned char *zl) {
- unsigned char *p, encoding;
- unsigned int l, lsize;
- long long value;
+ unsigned char *p;
+ zlentry entry;
printf("{total bytes %d} {length %u}\n",ZIPLIST_BYTES(zl), ZIPLIST_LENGTH(zl));
- p = ziplistHead(zl);
+ p = ZIPLIST_ENTRY_HEAD(zl);
while(*p != ZIP_END) {
- l = zipDecodeLength(p,&lsize);
- printf("{header %u, payload %u} ",lsize,l);
- encoding = ZIP_ENCODING(p);
- p += lsize;
- if (encoding == ZIP_ENC_RAW) {
- fwrite(p,l,1,stdout);
+ entry = zipEntry(p);
+ printf("{offset %ld, header %u, payload %u} ",p-zl,entry.headersize,entry.len);
+ p += entry.headersize;
+ if (entry.encoding == ZIP_ENC_RAW) {
+ fwrite(p,entry.len,1,stdout);
} else {
- printf("%lld", zipLoadInteger(p,encoding));
+ printf("%lld", zipLoadInteger(p,entry.encoding));
}
printf("\n");
- p += l;
+ p += entry.len;
}
printf("{end}\n\n");
}
#ifdef ZIPLIST_TEST_MAIN
+#include <sys/time.h>
unsigned char *createList() {
unsigned char *zl = ziplistNew();
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;
}
+long long usec(void) {
+ struct timeval tv;
+ gettimeofday(&tv,NULL);
+ return (((long long)tv.tv_sec)*1000000)+tv.tv_usec;
+}
+
+void stress(int pos, int num, int maxsize, int dnum) {
+ int i,j,k;
+ unsigned char *zl;
+ char posstr[2][5] = { "HEAD", "TAIL" };
+ long long start;
+ for (i = 0; i < maxsize; i+=dnum) {
+ zl = ziplistNew();
+ for (j = 0; j < i; j++) {
+ zl = ziplistPush(zl,(unsigned char*)"quux",4,ZIPLIST_TAIL);
+ }
+
+ /* Do num times a push+pop from pos */
+ start = usec();
+ for (k = 0; k < num; k++) {
+ zl = ziplistPush(zl,(unsigned char*)"quux",4,pos);
+ zl = ziplistDeleteRange(zl,0,1);
+ }
+ printf("List size: %8d, bytes: %8d, %dx push+pop (%s): %6lld usec\n",
+ i,ZIPLIST_BYTES(zl),num,posstr[pos],usec()-start);
+ zfree(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 head: %s (length %ld)\n", s, sdslen(s));
ziplistRepr(zl);
+ zl = ziplistPop(zl, &s, ZIPLIST_TAIL);
+ printf("Pop tail: %s (length %ld)\n", s, sdslen(s));
+ ziplistRepr(zl);
+
+ zl = ziplistPop(zl, &s, ZIPLIST_TAIL);
+ 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");
}
}
printf("\n");
ziplistRepr(zl);
- printf("\n");
+ }
+
+ 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,(unsigned char*)"hello",5)) {
+ printf("ERROR: not \"hello\"\n");
+ return 1;
+ }
+ if (ziplistCompare(p,(unsigned char*)"hella",5)) {
+ printf("ERROR: \"hella\"\n");
+ return 1;
+ }
+
+ p = ziplistIndex(zl,3);
+ if (!ziplistCompare(p,(unsigned char*)"1024",4)) {
+ printf("ERROR: not \"1024\"\n");
+ return 1;
+ }
+ if (ziplistCompare(p,(unsigned char*)"1025",4)) {
+ printf("ERROR: \"1025\"\n");
+ return 1;
+ }
+ printf("SUCCESS\n");
+ }
+
+ printf("Stress with variable ziplist size:\n");
+ {
+ stress(ZIPLIST_HEAD,100000,16384,256);
+ stress(ZIPLIST_TAIL,100000,16384,256);
}
return 0;
}
+
#endif
projects / redis.git / blobdiff