diff options
Diffstat (limited to 'src/ziplist.c')
| -rw-r--r-- | src/ziplist.c | 959 |
1 files changed, 959 insertions, 0 deletions
diff --git a/src/ziplist.c b/src/ziplist.c new file mode 100644 index 000000000..4b9d0fadc --- /dev/null +++ b/src/ziplist.c @@ -0,0 +1,959 @@ +/* Memory layout of a ziplist, containing "foo", "bar", "quux": + * <zlbytes><zllen><len>"foo"<len>"bar"<len>"quux" + * + * <zlbytes> is an unsigned integer to hold the number of bytes that + * the ziplist occupies. This is stored to not have to traverse the ziplist + * to know the new length when pushing. + * + * <zllen> is the number of items in the ziplist. When this value is + * greater than 254, we need to traverse the entire list to know + * how many items it holds. + * + * <len> is the number of bytes occupied by a single entry. When this + * number is greater than 253, the length will occupy 5 bytes, where + * the extra bytes contain an unsigned integer to hold the length. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <stdint.h> +#include <assert.h> +#include <limits.h> +#include "zmalloc.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_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_INLINE 0 +#define ZIP_LEN_UINT16 1 +#define ZIP_LEN_UINT32 2 + +/* Utility macros */ +#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) < 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(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); +} + +/* Decode the encoded length pointed by 'p'. If a pointer to 'lensize' is + * provided, it is set to the number of bytes required to encode the length. */ +static unsigned int zipDecodeLength(unsigned char *p, unsigned int *lensize) { + unsigned char encoding = ZIP_ENCODING(p), lenenc; + unsigned int len; + + if (encoding == ZIP_ENC_RAW) { + lenenc = (p[0] >> 4) & 0x3; + if (lenenc == ZIP_LEN_INLINE) { + len = p[0] & 0xf; + if (lensize) *lensize = 1; + } else if (lenenc == ZIP_LEN_UINT16) { + len = p[1] | (p[2] << 8); + if (lensize) *lensize = 3; + } else { + len = p[1] | (p[2] << 8) | (p[3] << 16) | (p[4] << 24); + if (lensize) *lensize = 5; + } + } else { + len = zipEncodingSize(encoding); + if (lensize) *lensize = 1; + } + return len; +} + +/* Encode the length 'l' writing it in 'p'. If p is NULL it just returns + * the amount of bytes required to encode such a length. */ +static unsigned int zipEncodeLength(unsigned char *p, char encoding, unsigned int rawlen) { + unsigned char len = 1, lenenc, buf[5]; + if (encoding == ZIP_ENC_RAW) { + if (rawlen <= 0xf) { + if (!p) return len; + lenenc = ZIP_LEN_INLINE; + buf[0] = rawlen; + } else if (rawlen <= 0xffff) { + len += 2; + if (!p) return len; + lenenc = ZIP_LEN_UINT16; + buf[1] = (rawlen ) & 0xff; + buf[2] = (rawlen >> 8) & 0xff; + } else { + len += 4; + if (!p) return len; + lenenc = ZIP_LEN_UINT32; + buf[1] = (rawlen ) & 0xff; + buf[2] = (rawlen >> 8) & 0xff; + buf[3] = (rawlen >> 16) & 0xff; + buf[4] = (rawlen >> 24) & 0xff; + } + buf[0] = (lenenc << 4) | (buf[0] & 0xf); + } + if (!p) return len; + + /* Apparently we need to store the length in 'p' */ + buf[0] = (encoding << 6) | (buf[0] & 0x3f); + memcpy(p,buf,len); + 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, unsigned char *encoding) { + long long value; + char *eptr; + + if (entry[0] == '-' || (entry[0] >= '0' && entry[0] <= '9')) { + value = strtoll((char*)entry,&eptr,10); + if (eptr[0] != '\0') return 0; + 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_INT64; + } + *v = value; + return 1; + } + return 0; +} + +/* Store integer 'value' at 'p', encoded as 'encoding' */ +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 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 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) { + zlentry e = zipEntry(p); + return e.headersize + e.len; +} + +/* Create a new empty ziplist. */ +unsigned char *ziplistNew(void) { + 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; +} + +/* Resize the ziplist. */ +static unsigned char *ziplistResize(unsigned char *zl, unsigned int len) { + zl = zrealloc(zl,len); + ZIPLIST_BYTES(zl) = len; + zl[len-1] = ZIP_END; + return zl; +} + +/* 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 zl; +} + +/* 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(s,&value,&encoding)) { + reqlen = zipEncodingSize(encoding); + } else { + reqlen = slen; + } + + /* 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 { + /* This element will be the new tail. */ + ZIPLIST_TAIL_OFFSET(zl) = p-zl; + } + + /* Write the entry */ + p += zipPrevEncodeLength(p,prevlen); + p += zipEncodeLength(p,encoding,slen); + if (encoding != ZIP_ENC_RAW) { + zipSaveInteger(p,value,encoding); + } else { + 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); +} + +/* 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[0] == ZIP_END || index > 0) ? NULL : p; +} + +/* Return pointer to next entry in ziplist. */ +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 **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 (sval) { + *sval = zipLoadInteger(p+entry.headersize,entry.encoding); + } + } + return 1; +} + +/* 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; + 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. + * 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; + zlentry entry; + + printf("{total bytes %d} {length %u}\n",ZIPLIST_BYTES(zl), ZIPLIST_LENGTH(zl)); + p = ZIPLIST_ENTRY_HEAD(zl); + while(*p != ZIP_END) { + 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,entry.encoding)); + } + printf("\n"); + p += entry.len; + } + printf("{end}\n\n"); +} + +#ifdef ZIPLIST_TEST_MAIN +#include <sys/time.h> + +unsigned char *createList() { + unsigned char *zl = ziplistNew(); + zl = ziplistPush(zl, (unsigned char*)"foo", 3, ZIPLIST_TAIL); + zl = ziplistPush(zl, (unsigned char*)"quux", 4, ZIPLIST_TAIL); + zl = ziplistPush(zl, (unsigned char*)"hello", 5, ZIPLIST_HEAD); + zl = ziplistPush(zl, (unsigned char*)"1024", 4, ZIPLIST_TAIL); + return zl; +} + +unsigned char *createIntList() { + unsigned char *zl = ziplistNew(); + char buf[32]; + + sprintf(buf, "100"); + zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_TAIL); + sprintf(buf, "128000"); + zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_TAIL); + sprintf(buf, "-100"); + zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_HEAD); + sprintf(buf, "4294967296"); + zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_HEAD); + sprintf(buf, "non integer"); + zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), ZIPLIST_TAIL); + sprintf(buf, "much much longer non integer"); + 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); + } +} + +void pop(unsigned char *zl, int where) { + unsigned char *p, *vstr; + unsigned int vlen; + long long vlong; + + p = ziplistIndex(zl,where == ZIPLIST_HEAD ? 0 : -1); + if (ziplistGet(p,&vstr,&vlen,&vlong)) { + if (where == ZIPLIST_HEAD) + printf("Pop head: "); + else + printf("Pop tail: "); + + if (vstr) + fwrite(vstr,vlen,1,stdout); + else + printf("%lld", vlong); + + printf("\n"); + ziplistDeleteRange(zl,-1,1); + } else { + printf("ERROR: Could not pop\n"); + exit(1); + } +} + +int main(int argc, char **argv) { + unsigned char *zl, *p; + unsigned char *entry; + unsigned int elen; + long long value; + + zl = createIntList(); + ziplistRepr(zl); + + zl = createList(); + ziplistRepr(zl); + + pop(zl,ZIPLIST_TAIL); + ziplistRepr(zl); + + pop(zl,ZIPLIST_HEAD); + ziplistRepr(zl); + + pop(zl,ZIPLIST_TAIL); + ziplistRepr(zl); + + pop(zl,ZIPLIST_TAIL); + 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(); + p = ziplistIndex(zl, 0); + while (ziplistGet(p, &entry, &elen, &value)) { + printf("Entry: "); + if (entry) { + fwrite(entry,elen,1,stdout); + } else { + printf("%lld", value); + } + p = ziplistNext(zl,p); + printf("\n"); + } + printf("\n"); + } + + printf("Iterate list from 1 to end:\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 = ziplistNext(zl,p); + printf("\n"); + } + printf("\n"); + } + + printf("Iterate list from 2 to end:\n"); + { + zl = createList(); + p = ziplistIndex(zl, 2); + while (ziplistGet(p, &entry, &elen, &value)) { + printf("Entry: "); + if (entry) { + fwrite(entry,elen,1,stdout); + } else { + printf("%lld", value); + } + p = ziplistNext(zl,p); + printf("\n"); + } + printf("\n"); + } + + printf("Iterate starting out of range:\n"); + { + zl = createList(); + p = ziplistIndex(zl, 4); + if (!ziplistGet(p, &entry, &elen, &value)) { + printf("No entry\n"); + } else { + printf("ERROR\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(); + zl = ziplistDeleteRange(zl, 0, 1); + ziplistRepr(zl); + } + + printf("Delete inclusive range 0,1:\n"); + { + zl = createList(); + zl = ziplistDeleteRange(zl, 0, 2); + ziplistRepr(zl); + } + + printf("Delete inclusive range 1,2:\n"); + { + zl = createList(); + zl = ziplistDeleteRange(zl, 1, 2); + ziplistRepr(zl); + } + + printf("Delete with start index out of range:\n"); + { + zl = createList(); + zl = ziplistDeleteRange(zl, 5, 1); + ziplistRepr(zl); + } + + printf("Delete with num overflow:\n"); + { + zl = createList(); + zl = ziplistDeleteRange(zl, 1, 5); + ziplistRepr(zl); + } + + printf("Delete foo while iterating:\n"); + { + zl = createList(); + 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); + } else { + printf("Entry: "); + if (entry) { + fwrite(entry,elen,1,stdout); + } else { + printf("%lld",value); + } + p = ziplistNext(zl,p); + printf("\n"); + } + } + 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,(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 |