X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/b882056c93f3e3afe5fde9d62fb569ce30a76a76..7eb850ef0e437323e2d84157ddc2e6e82af57bbc:/src/ziplist.c?ds=sidebyside diff --git a/src/ziplist.c b/src/ziplist.c index 5254423d..23bad45c 100644 --- a/src/ziplist.c +++ b/src/ziplist.c @@ -52,12 +52,23 @@ * String value with length less than or equal to 16383 bytes (14 bits). * |10______|qqqqqqqq|rrrrrrrr|ssssssss|tttttttt| - 5 bytes * String value with length greater than or equal to 16384 bytes. - * |1100____| - 1 byte + * |11000000| - 1 byte * Integer encoded as int16_t (2 bytes). - * |1101____| - 1 byte + * |11010000| - 1 byte * Integer encoded as int32_t (4 bytes). - * |1110____| - 1 byte + * |11100000| - 1 byte * Integer encoded as int64_t (8 bytes). + * |11110000| - 1 byte + * Integer encoded as 24 bit signed (3 bytes). + * |11111110| - 1 byte + * Integer encoded as 8 bit signed (1 byte). + * |1111xxxx| - (with xxxx between 0000 and 1101) immediate 4 bit integer. + * Unsigned integer from 0 to 12. The encoded value is actually from + * 1 to 13 because 0000 and 1111 can not be used, so 1 should be + * subtracted from the encoded 4 bit value to obtain the right value. + * |11111111| - End of ziplist. + * + * All the integers are represented in little endian byte order. */ #include @@ -67,24 +78,35 @@ #include #include #include "zmalloc.h" +#include "util.h" #include "ziplist.h" - -int ll2string(char *s, size_t len, long long value); +#include "endianconv.h" #define ZIP_END 255 #define ZIP_BIGLEN 254 /* Different encoding/length possibilities */ +#define ZIP_STR_MASK 0xc0 +#define ZIP_INT_MASK 0x30 #define ZIP_STR_06B (0 << 6) #define ZIP_STR_14B (1 << 6) #define ZIP_STR_32B (2 << 6) #define ZIP_INT_16B (0xc0 | 0<<4) #define ZIP_INT_32B (0xc0 | 1<<4) #define ZIP_INT_64B (0xc0 | 2<<4) +#define ZIP_INT_24B (0xc0 | 3<<4) +#define ZIP_INT_8B 0xfe +/* 4 bit integer immediate encoding */ +#define ZIP_INT_IMM_MASK 0x0f +#define ZIP_INT_IMM_MIN 0xf1 /* 11110001 */ +#define ZIP_INT_IMM_MAX 0xfd /* 11111101 */ +#define ZIP_INT_IMM_VAL(v) (v & ZIP_INT_IMM_MASK) -/* Macro's to determine type */ -#define ZIP_IS_STR(enc) (((enc) & 0xc0) < 0xc0) -#define ZIP_IS_INT(enc) (!ZIP_IS_STR(enc) && ((enc) & 0x30) < 0x30) +#define INT24_MAX 0x7fffff +#define INT24_MIN (-INT24_MAX - 1) + +/* Macro to determine type */ +#define ZIP_IS_STR(enc) (((enc) & ZIP_STR_MASK) < ZIP_STR_MASK) /* Utility macros */ #define ZIPLIST_BYTES(zl) (*((uint32_t*)(zl))) @@ -92,13 +114,15 @@ int ll2string(char *s, size_t len, long long value); #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) +#define ZIPLIST_ENTRY_TAIL(zl) ((zl)+intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))) +#define ZIPLIST_ENTRY_END(zl) ((zl)+intrev32ifbe(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; } + if (ZIPLIST_LENGTH(zl) < UINT16_MAX) \ + ZIPLIST_LENGTH(zl) = intrev16ifbe(intrev16ifbe(ZIPLIST_LENGTH(zl))+incr); \ +} typedef struct zlentry { unsigned int prevrawlensize, prevrawlen; @@ -108,57 +132,25 @@ typedef struct zlentry { unsigned char *p; } zlentry; -/* Return the encoding pointer to by 'p'. */ -static unsigned int zipEntryEncoding(unsigned char *p) { - /* String encoding: 2 MSBs */ - unsigned char b = p[0] & 0xc0; - if (b < 0xc0) { - return b; - } else { - /* Integer encoding: 4 MSBs */ - return p[0] & 0xf0; - } - assert(NULL); -} +/* Extract the encoding from the byte pointed by 'ptr' and set it into + * 'encoding'. */ +#define ZIP_ENTRY_ENCODING(ptr, encoding) do { \ + (encoding) = (ptr[0]); \ + if ((encoding) < ZIP_STR_MASK) (encoding) &= ZIP_STR_MASK; \ +} while(0) /* Return bytes needed to store integer encoded by 'encoding' */ static unsigned int zipIntSize(unsigned char encoding) { switch(encoding) { - case ZIP_INT_16B: return sizeof(int16_t); - case ZIP_INT_32B: return sizeof(int32_t); - case ZIP_INT_64B: return sizeof(int64_t); + case ZIP_INT_8B: return 1; + case ZIP_INT_16B: return 2; + case ZIP_INT_24B: return 3; + case ZIP_INT_32B: return 4; + case ZIP_INT_64B: return 8; + default: return 0; /* 4 bit immediate */ } 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 = zipEntryEncoding(p); - unsigned int len; - - if (ZIP_IS_STR(encoding)) { - switch(encoding) { - case ZIP_STR_06B: - len = p[0] & 0x3f; - if (lensize) *lensize = 1; - break; - case ZIP_STR_14B: - len = ((p[0] & 0x3f) << 6) | p[1]; - if (lensize) *lensize = 2; - break; - case ZIP_STR_32B: - len = (p[1] << 24) | (p[2] << 16) | (p[3] << 8) | p[4]; - if (lensize) *lensize = 5; - break; - default: - assert(NULL); - } - } else { - len = zipIntSize(encoding); - if (lensize) *lensize = 1; - } - return len; + return 0; } /* Encode the length 'l' writing it in 'p'. If p is NULL it just returns @@ -197,17 +189,33 @@ static unsigned int zipEncodeLength(unsigned char *p, unsigned char encoding, un 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; -} +/* Decode the length encoded in 'ptr'. The 'encoding' variable will hold the + * entries encoding, the 'lensize' variable will hold the number of bytes + * required to encode the entries length, and the 'len' variable will hold the + * entries length. */ +#define ZIP_DECODE_LENGTH(ptr, encoding, lensize, len) do { \ + ZIP_ENTRY_ENCODING((ptr), (encoding)); \ + if ((encoding) < ZIP_STR_MASK) { \ + if ((encoding) == ZIP_STR_06B) { \ + (lensize) = 1; \ + (len) = (ptr)[0] & 0x3f; \ + } else if ((encoding) == ZIP_STR_14B) { \ + (lensize) = 2; \ + (len) = (((ptr)[0] & 0x3f) << 8) | (ptr)[1]; \ + } else if (encoding == ZIP_STR_32B) { \ + (lensize) = 5; \ + (len) = ((ptr)[1] << 24) | \ + ((ptr)[2] << 16) | \ + ((ptr)[3] << 8) | \ + ((ptr)[4]); \ + } else { \ + assert(NULL); \ + } \ + } else { \ + (lensize) = 1; \ + (len) = zipIntSize(encoding); \ + } \ +} while(0); /* 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. */ @@ -221,6 +229,7 @@ static unsigned int zipPrevEncodeLength(unsigned char *p, unsigned int len) { } else { p[0] = ZIP_BIGLEN; memcpy(p+1,&len,sizeof(len)); + memrev32ifbe(p+1); return 1+sizeof(len); } } @@ -232,40 +241,65 @@ static void zipPrevEncodeLengthForceLarge(unsigned char *p, unsigned int len) { if (p == NULL) return; p[0] = ZIP_BIGLEN; memcpy(p+1,&len,sizeof(len)); + memrev32ifbe(p+1); } -/* Return the difference in number of bytes needed to store the new length - * "len" on the entry pointed to by "p". */ +/* Decode the number of bytes required to store the length of the previous + * element, from the perspective of the entry pointed to by 'ptr'. */ +#define ZIP_DECODE_PREVLENSIZE(ptr, prevlensize) do { \ + if ((ptr)[0] < ZIP_BIGLEN) { \ + (prevlensize) = 1; \ + } else { \ + (prevlensize) = 5; \ + } \ +} while(0); + +/* Decode the length of the previous element, from the perspective of the entry + * pointed to by 'ptr'. */ +#define ZIP_DECODE_PREVLEN(ptr, prevlensize, prevlen) do { \ + ZIP_DECODE_PREVLENSIZE(ptr, prevlensize); \ + if ((prevlensize) == 1) { \ + (prevlen) = (ptr)[0]; \ + } else if ((prevlensize) == 5) { \ + assert(sizeof((prevlensize)) == 4); \ + memcpy(&(prevlen), ((char*)(ptr)) + 1, 4); \ + memrev32ifbe(&prevlen); \ + } \ +} while(0); + +/* Return the difference in number of bytes needed to store the length of the + * previous element 'len', in 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; + ZIP_DECODE_PREVLENSIZE(p, prevlensize); + return zipPrevEncodeLength(NULL, len) - prevlensize; +} + +/* Return the total number of bytes used by the entry pointed to by 'p'. */ +static unsigned int zipRawEntryLength(unsigned char *p) { + unsigned int prevlensize, encoding, lensize, len; + ZIP_DECODE_PREVLENSIZE(p, prevlensize); + ZIP_DECODE_LENGTH(p + prevlensize, encoding, lensize, len); + return prevlensize + lensize + len; } /* Check if string pointed to by 'entry' can be encoded as an integer. * Stores the integer value in 'v' and its encoding in 'encoding'. */ static int zipTryEncoding(unsigned char *entry, unsigned int entrylen, long long *v, unsigned char *encoding) { long long value; - char *eptr; - char buf[32]; if (entrylen >= 32 || entrylen == 0) return 0; - if (entry[0] == '-' || (entry[0] >= '0' && entry[0] <= '9')) { - int slen; - - /* Perform a back-and-forth conversion to make sure that - * the string turned into an integer is not losing any info. */ - memcpy(buf,entry,entrylen); - buf[entrylen] = '\0'; - value = strtoll(buf,&eptr,10); - if (eptr[0] != '\0') return 0; - slen = ll2string(buf,32,value); - if (entrylen != (unsigned)slen || memcmp(buf,entry,slen)) return 0; - + if (string2ll((char*)entry,entrylen,&value)) { /* Great, the string can be encoded. Check what's the smallest * of our encoding types that can hold this value. */ - if (value >= INT16_MIN && value <= INT16_MAX) { + if (value >= 0 && value <= 12) { + *encoding = ZIP_INT_IMM_MIN+value; + } else if (value >= INT8_MIN && value <= INT8_MAX) { + *encoding = ZIP_INT_8B; + } else if (value >= INT16_MIN && value <= INT16_MAX) { *encoding = ZIP_INT_16B; + } else if (value >= INT24_MIN && value <= INT24_MAX) { + *encoding = ZIP_INT_24B; } else if (value >= INT32_MIN && value <= INT32_MAX) { *encoding = ZIP_INT_32B; } else { @@ -282,15 +316,26 @@ static void zipSaveInteger(unsigned char *p, int64_t value, unsigned char encodi int16_t i16; int32_t i32; int64_t i64; - if (encoding == ZIP_INT_16B) { + if (encoding == ZIP_INT_8B) { + ((int8_t*)p)[0] = (int8_t)value; + } else if (encoding == ZIP_INT_16B) { i16 = value; memcpy(p,&i16,sizeof(i16)); + memrev16ifbe(p); + } else if (encoding == ZIP_INT_24B) { + i32 = value<<8; + memrev32ifbe(&i32); + memcpy(p,((uint8_t*)&i32)+1,sizeof(i32)-sizeof(uint8_t)); } else if (encoding == ZIP_INT_32B) { i32 = value; memcpy(p,&i32,sizeof(i32)); + memrev32ifbe(p); } else if (encoding == ZIP_INT_64B) { i64 = value; memcpy(p,&i64,sizeof(i64)); + memrev64ifbe(p); + } else if (encoding >= ZIP_INT_IMM_MIN && encoding <= ZIP_INT_IMM_MAX) { + /* Nothing to do, the value is stored in the encoding itself. */ } else { assert(NULL); } @@ -300,16 +345,28 @@ static void zipSaveInteger(unsigned char *p, int64_t value, unsigned char encodi static int64_t zipLoadInteger(unsigned char *p, unsigned char encoding) { int16_t i16; int32_t i32; - int64_t i64, ret; - if (encoding == ZIP_INT_16B) { + int64_t i64, ret = 0; + if (encoding == ZIP_INT_8B) { + ret = ((int8_t*)p)[0]; + } else if (encoding == ZIP_INT_16B) { memcpy(&i16,p,sizeof(i16)); + memrev16ifbe(&i16); ret = i16; } else if (encoding == ZIP_INT_32B) { memcpy(&i32,p,sizeof(i32)); + memrev32ifbe(&i32); ret = i32; + } else if (encoding == ZIP_INT_24B) { + i32 = 0; + memcpy(((uint8_t*)&i32)+1,p,sizeof(i32)-sizeof(uint8_t)); + memrev32ifbe(&i32); + ret = i32>>8; } else if (encoding == ZIP_INT_64B) { memcpy(&i64,p,sizeof(i64)); + memrev64ifbe(&i64); ret = i64; + } else if (encoding >= ZIP_INT_IMM_MIN && encoding <= ZIP_INT_IMM_MAX) { + ret = (encoding & ZIP_INT_IMM_MASK)-1; } else { assert(NULL); } @@ -319,26 +376,20 @@ static int64_t zipLoadInteger(unsigned char *p, unsigned char encoding) { /* 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 = zipEntryEncoding(p+e.prevrawlensize); + + ZIP_DECODE_PREVLEN(p, e.prevrawlensize, e.prevrawlen); + ZIP_DECODE_LENGTH(p + e.prevrawlensize, e.encoding, e.lensize, e.len); + e.headersize = e.prevrawlensize + e.lensize; 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_BYTES(zl) = intrev32ifbe(bytes); + ZIPLIST_TAIL_OFFSET(zl) = intrev32ifbe(ZIPLIST_HEADER_SIZE); ZIPLIST_LENGTH(zl) = 0; zl[bytes-1] = ZIP_END; return zl; @@ -347,7 +398,7 @@ unsigned char *ziplistNew(void) { /* Resize the ziplist. */ static unsigned char *ziplistResize(unsigned char *zl, unsigned int len) { zl = zrealloc(zl,len); - ZIPLIST_BYTES(zl) = len; + ZIPLIST_BYTES(zl) = intrev32ifbe(len); zl[len-1] = ZIP_END; return zl; } @@ -373,8 +424,8 @@ static unsigned char *ziplistResize(unsigned char *zl, unsigned int len) { * The pointer "p" points to the first entry that does NOT need to be * updated, i.e. consecutive fields MAY need an update. */ static unsigned char *__ziplistCascadeUpdate(unsigned char *zl, unsigned char *p) { - unsigned int curlen = ZIPLIST_BYTES(zl), rawlen, rawlensize; - unsigned int offset, noffset, extra; + size_t curlen = intrev32ifbe(ZIPLIST_BYTES(zl)), rawlen, rawlensize; + size_t offset, noffset, extra; unsigned char *np; zlentry cur, next; @@ -396,12 +447,19 @@ static unsigned char *__ziplistCascadeUpdate(unsigned char *zl, unsigned char *p offset = p-zl; extra = rawlensize-next.prevrawlensize; zl = ziplistResize(zl,curlen+extra); - ZIPLIST_TAIL_OFFSET(zl) += extra; p = zl+offset; - /* Move the tail to the back. */ + /* Current pointer and offset for next element. */ np = p+rawlen; noffset = np-zl; + + /* Update tail offset when next element is not the tail element. */ + if ((zl+intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))) != np) { + ZIPLIST_TAIL_OFFSET(zl) = + intrev32ifbe(intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))+extra); + } + + /* Move the tail to the back. */ memmove(np+rawlensize, np+next.prevrawlensize, curlen-noffset-next.prevrawlensize-1); @@ -409,6 +467,7 @@ static unsigned char *__ziplistCascadeUpdate(unsigned char *zl, unsigned char *p /* Advance the cursor */ p += rawlen; + curlen += extra; } else { if (next.prevrawlensize > rawlensize) { /* This would result in shrinking, which we want to avoid. @@ -428,7 +487,8 @@ static unsigned char *__ziplistCascadeUpdate(unsigned char *zl, unsigned char *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 offset, nextdiff = 0; + size_t offset; + int nextdiff = 0; zlentry first, tail; first = zipEntry(p); @@ -440,33 +500,39 @@ static unsigned char *__ziplistDelete(unsigned char *zl, unsigned char *p, unsig 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. */ + /* Storing `prevrawlen` in this entry may increase or decrease the + * number of bytes required compare to the current `prevrawlen`. + * There always is room to store this, because it was previously + * stored by an entry that is now being deleted. */ nextdiff = zipPrevLenByteDiff(p,first.prevrawlen); - zipPrevEncodeLength(p-nextdiff,first.prevrawlen); + p -= nextdiff; + zipPrevEncodeLength(p,first.prevrawlen); /* Update offset for tail */ - ZIPLIST_TAIL_OFFSET(zl) -= totlen; + ZIPLIST_TAIL_OFFSET(zl) = + intrev32ifbe(intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))-totlen); /* When the tail contains more than one entry, we need to take * "nextdiff" in account as well. Otherwise, a change in the * size of prevlen doesn't have an effect on the *tail* offset. */ tail = zipEntry(p); - if (p[tail.headersize+tail.len] != ZIP_END) - ZIPLIST_TAIL_OFFSET(zl) += nextdiff; + if (p[tail.headersize+tail.len] != ZIP_END) { + ZIPLIST_TAIL_OFFSET(zl) = + intrev32ifbe(intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))+nextdiff); + } /* Move tail to the front of the ziplist */ - memmove(first.p,p-nextdiff,ZIPLIST_BYTES(zl)-(p-zl)-1+nextdiff); + memmove(first.p,p, + intrev32ifbe(ZIPLIST_BYTES(zl))-(p-zl)-1); } else { /* The entire tail was deleted. No need to move memory. */ - ZIPLIST_TAIL_OFFSET(zl) = (first.p-zl)-first.prevrawlen; + ZIPLIST_TAIL_OFFSET(zl) = + intrev32ifbe((first.p-zl)-first.prevrawlen); } /* Resize and update length */ offset = first.p-zl; - zl = ziplistResize(zl, ZIPLIST_BYTES(zl)-totlen+nextdiff); + zl = ziplistResize(zl, intrev32ifbe(ZIPLIST_BYTES(zl))-totlen+nextdiff); ZIPLIST_INCR_LENGTH(zl,-deleted); p = zl+offset; @@ -480,10 +546,13 @@ static unsigned char *__ziplistDelete(unsigned char *zl, unsigned char *p, unsig /* 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; + size_t curlen = intrev32ifbe(ZIPLIST_BYTES(zl)), reqlen, prevlen = 0; + size_t offset; + int nextdiff = 0; unsigned char encoding = 0; - long long value; + long long value = 123456789; /* initialized to avoid warning. Using a value + that is easy to see if for some reason + we use it uninitialized. */ zlentry entry, tail; /* Find out prevlen for the entry that is inserted. */ @@ -530,17 +599,20 @@ static unsigned char *__ziplistInsert(unsigned char *zl, unsigned char *p, unsig zipPrevEncodeLength(p+reqlen,reqlen); /* Update offset for tail */ - ZIPLIST_TAIL_OFFSET(zl) += reqlen; + ZIPLIST_TAIL_OFFSET(zl) = + intrev32ifbe(intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))+reqlen); /* When the tail contains more than one entry, we need to take * "nextdiff" in account as well. Otherwise, a change in the * size of prevlen doesn't have an effect on the *tail* offset. */ tail = zipEntry(p+reqlen); - if (p[reqlen+tail.headersize+tail.len] != ZIP_END) - ZIPLIST_TAIL_OFFSET(zl) += nextdiff; + if (p[reqlen+tail.headersize+tail.len] != ZIP_END) { + ZIPLIST_TAIL_OFFSET(zl) = + intrev32ifbe(intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))+nextdiff); + } } else { /* This element will be the new tail. */ - ZIPLIST_TAIL_OFFSET(zl) = p-zl; + ZIPLIST_TAIL_OFFSET(zl) = intrev32ifbe(p-zl); } /* When nextdiff != 0, the raw length of the next entry has changed, so @@ -594,7 +666,12 @@ unsigned char *ziplistIndex(unsigned char *zl, int index) { return (p[0] == ZIP_END || index > 0) ? NULL : p; } -/* Return pointer to next entry in ziplist. */ +/* Return pointer to next entry in ziplist. + * + * zl is the pointer to the ziplist + * p is the pointer to the current element + * + * The element after 'p' is returned, otherwise NULL if we are at the end. */ unsigned char *ziplistNext(unsigned char *zl, unsigned char *p) { ((void) zl); @@ -603,10 +680,14 @@ unsigned char *ziplistNext(unsigned char *zl, unsigned char *p) { * 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; } + + p += zipRawEntryLength(p); + if (p[0] == ZIP_END) { + return NULL; + } + + return p; } /* Return pointer to previous entry in ziplist. */ @@ -660,7 +741,7 @@ unsigned char *ziplistInsert(unsigned char *zl, unsigned char *p, unsigned char * 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; + size_t offset = *p-zl; zl = __ziplistDelete(zl,*p,1); /* Store pointer to current element in p, because ziplistDelete will @@ -693,22 +774,82 @@ unsigned int ziplistCompare(unsigned char *p, unsigned char *sstr, unsigned int return 0; } } else { - /* Try to compare encoded values */ + /* Try to compare encoded values. Don't compare encoding because + * different implementations may encoded integers differently. */ if (zipTryEncoding(sstr,slen,&sval,&sencoding)) { - if (entry.encoding == sencoding) { - zval = zipLoadInteger(p+entry.headersize,entry.encoding); - return zval == sval; - } + zval = zipLoadInteger(p+entry.headersize,entry.encoding); + return zval == sval; } } return 0; } +/* Find pointer to the entry equal to the specified entry. Skip 'skip' entries + * between every comparison. Returns NULL when the field could not be found. */ +unsigned char *ziplistFind(unsigned char *p, unsigned char *vstr, unsigned int vlen, unsigned int skip) { + int skipcnt = 0; + unsigned char vencoding = 0; + long long vll = 0; + + while (p[0] != ZIP_END) { + unsigned int prevlensize, encoding, lensize, len; + unsigned char *q; + + ZIP_DECODE_PREVLENSIZE(p, prevlensize); + ZIP_DECODE_LENGTH(p + prevlensize, encoding, lensize, len); + q = p + prevlensize + lensize; + + if (skipcnt == 0) { + /* Compare current entry with specified entry */ + if (ZIP_IS_STR(encoding)) { + if (len == vlen && memcmp(q, vstr, vlen) == 0) { + return p; + } + } else { + /* Find out if the searched field can be encoded. Note that + * we do it only the first time, once done vencoding is set + * to non-zero and vll is set to the integer value. */ + if (vencoding == 0) { + if (!zipTryEncoding(vstr, vlen, &vll, &vencoding)) { + /* If the entry can't be encoded we set it to + * UCHAR_MAX so that we don't retry again the next + * time. */ + vencoding = UCHAR_MAX; + } + /* Must be non-zero by now */ + assert(vencoding); + } + + /* Compare current entry with specified entry, do it only + * if vencoding != UCHAR_MAX because if there is no encoding + * possible for the field it can't be a valid integer. */ + if (vencoding != UCHAR_MAX) { + long long ll = zipLoadInteger(q, encoding); + if (ll == vll) { + return p; + } + } + } + + /* Reset skip count */ + skipcnt = skip; + } else { + /* Skip entry */ + skipcnt--; + } + + /* Move to next entry */ + p = q + len; + } + + return NULL; +} + /* Return length of ziplist. */ unsigned int ziplistLen(unsigned char *zl) { unsigned int len = 0; - if (ZIPLIST_LENGTH(zl) < UINT16_MAX) { - len = ZIPLIST_LENGTH(zl); + if (intrev16ifbe(ZIPLIST_LENGTH(zl)) < UINT16_MAX) { + len = intrev16ifbe(ZIPLIST_LENGTH(zl)); } else { unsigned char *p = zl+ZIPLIST_HEADER_SIZE; while (*p != ZIP_END) { @@ -717,14 +858,14 @@ unsigned int ziplistLen(unsigned char *zl) { } /* Re-store length if small enough */ - if (len < UINT16_MAX) ZIPLIST_LENGTH(zl) = len; + if (len < UINT16_MAX) ZIPLIST_LENGTH(zl) = intrev16ifbe(len); } return len; } -/* Return size in bytes of ziplist. */ -unsigned int ziplistSize(unsigned char *zl) { - return ZIPLIST_BYTES(zl); +/* Return ziplist blob size in bytes. */ +size_t ziplistBlobLen(unsigned char *zl) { + return intrev32ifbe(ZIPLIST_BYTES(zl)); } void ziplistRepr(unsigned char *zl) { @@ -736,9 +877,9 @@ void ziplistRepr(unsigned char *zl) { "{total bytes %d} " "{length %u}\n" "{tail offset %u}\n", - ZIPLIST_BYTES(zl), - ZIPLIST_LENGTH(zl), - ZIPLIST_TAIL_OFFSET(zl)); + intrev32ifbe(ZIPLIST_BYTES(zl)), + intrev16ifbe(ZIPLIST_LENGTH(zl)), + intrev32ifbe(ZIPLIST_TAIL_OFFSET(zl))); p = ZIPLIST_ENTRY_HEAD(zl); while(*p != ZIP_END) { entry = zipEntry(p); @@ -753,9 +894,9 @@ void ziplistRepr(unsigned char *zl) { "pls: %2u, " "payload %5u" "} ", - (long unsigned int)p, + (long unsigned)p, index, - p-zl, + (unsigned long) (p-zl), entry.headersize+entry.len, entry.headersize, entry.prevrawlen, @@ -764,10 +905,11 @@ void ziplistRepr(unsigned char *zl) { p += entry.headersize; if (ZIP_IS_STR(entry.encoding)) { if (entry.len > 40) { - fwrite(p,40,1,stdout); + if (fwrite(p,40,1,stdout) == 0) perror("fwrite"); printf("..."); } else { - fwrite(p,entry.len,1,stdout); + if (entry.len && + fwrite(p,entry.len,1,stdout) == 0) perror("fwrite"); } } else { printf("%lld", (long long) zipLoadInteger(p,entry.encoding)); @@ -781,6 +923,10 @@ void ziplistRepr(unsigned char *zl) { #ifdef ZIPLIST_TEST_MAIN #include +#include "adlist.h" +#include "sds.h" + +#define debug(f, ...) { if (DEBUG) printf(f, __VA_ARGS__); } unsigned char *createList() { unsigned char *zl = ziplistNew(); @@ -834,7 +980,7 @@ void stress(int pos, int num, int maxsize, int dnum) { 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); + i,intrev32ifbe(ZIPLIST_BYTES(zl)),num,posstr[pos],usec()-start); zfree(zl); } } @@ -852,7 +998,7 @@ void pop(unsigned char *zl, int where) { printf("Pop tail: "); if (vstr) - fwrite(vstr,vlen,1,stdout); + if (vlen && fwrite(vstr,vlen,1,stdout) == 0) perror("fwrite"); else printf("%lld", vlong); @@ -864,6 +1010,47 @@ void pop(unsigned char *zl, int where) { } } +int randstring(char *target, unsigned int min, unsigned int max) { + int p, len = min+rand()%(max-min+1); + int minval, maxval; + switch(rand() % 3) { + case 0: + minval = 0; + maxval = 255; + break; + case 1: + minval = 48; + maxval = 122; + break; + case 2: + minval = 48; + maxval = 52; + break; + default: + assert(NULL); + } + + while(p < len) + target[p++] = minval+rand()%(maxval-minval+1); + return len; +} + +void verify(unsigned char *zl, zlentry *e) { + int i; + int len = ziplistLen(zl); + zlentry _e; + + for (i = 0; i < len; i++) { + memset(&e[i], 0, sizeof(zlentry)); + e[i] = zipEntry(ziplistIndex(zl, i)); + + memset(&_e, 0, sizeof(zlentry)); + _e = zipEntry(ziplistIndex(zl, -len+i)); + + assert(memcmp(&e[i], &_e, sizeof(zlentry)) == 0); + } +} + int main(int argc, char **argv) { unsigned char *zl, *p; unsigned char *entry; @@ -901,7 +1088,7 @@ int main(int argc, char **argv) { return 1; } if (entry) { - fwrite(entry,elen,1,stdout); + if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); printf("\n"); } else { printf("%lld\n", value); @@ -931,7 +1118,7 @@ int main(int argc, char **argv) { return 1; } if (entry) { - fwrite(entry,elen,1,stdout); + if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); printf("\n"); } else { printf("%lld\n", value); @@ -948,7 +1135,7 @@ int main(int argc, char **argv) { return 1; } if (entry) { - fwrite(entry,elen,1,stdout); + if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); printf("\n"); } else { printf("%lld\n", value); @@ -976,7 +1163,7 @@ int main(int argc, char **argv) { while (ziplistGet(p, &entry, &elen, &value)) { printf("Entry: "); if (entry) { - fwrite(entry,elen,1,stdout); + if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); } else { printf("%lld", value); } @@ -993,7 +1180,7 @@ int main(int argc, char **argv) { while (ziplistGet(p, &entry, &elen, &value)) { printf("Entry: "); if (entry) { - fwrite(entry,elen,1,stdout); + if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); } else { printf("%lld", value); } @@ -1010,7 +1197,7 @@ int main(int argc, char **argv) { while (ziplistGet(p, &entry, &elen, &value)) { printf("Entry: "); if (entry) { - fwrite(entry,elen,1,stdout); + if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); } else { printf("%lld", value); } @@ -1039,7 +1226,7 @@ int main(int argc, char **argv) { while (ziplistGet(p, &entry, &elen, &value)) { printf("Entry: "); if (entry) { - fwrite(entry,elen,1,stdout); + if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); } else { printf("%lld", value); } @@ -1056,7 +1243,7 @@ int main(int argc, char **argv) { while (ziplistGet(p, &entry, &elen, &value)) { printf("Entry: "); if (entry) { - fwrite(entry,elen,1,stdout); + if (elen && fwrite(entry,elen,1,stdout) == 0) perror("fwrite"); } else { printf("%lld", value); } @@ -1113,7 +1300,8 @@ int main(int argc, char **argv) { } else { printf("Entry: "); if (entry) { - fwrite(entry,elen,1,stdout); + if (elen && fwrite(entry,elen,1,stdout) == 0) + perror("fwrite"); } else { printf("%lld",value); } @@ -1125,6 +1313,62 @@ int main(int argc, char **argv) { ziplistRepr(zl); } + printf("Regression test for >255 byte strings:\n"); + { + char v1[257],v2[257]; + memset(v1,'x',256); + memset(v2,'y',256); + zl = ziplistNew(); + zl = ziplistPush(zl,(unsigned char*)v1,strlen(v1),ZIPLIST_TAIL); + zl = ziplistPush(zl,(unsigned char*)v2,strlen(v2),ZIPLIST_TAIL); + + /* Pop values again and compare their value. */ + p = ziplistIndex(zl,0); + assert(ziplistGet(p,&entry,&elen,&value)); + assert(strncmp(v1,(char*)entry,elen) == 0); + p = ziplistIndex(zl,1); + assert(ziplistGet(p,&entry,&elen,&value)); + assert(strncmp(v2,(char*)entry,elen) == 0); + printf("SUCCESS\n\n"); + } + + printf("Regression test deleting next to last entries:\n"); + { + char v[3][257]; + zlentry e[3]; + int i; + + for (i = 0; i < (sizeof(v)/sizeof(v[0])); i++) { + memset(v[i], 'a' + i, sizeof(v[0])); + } + + v[0][256] = '\0'; + v[1][ 1] = '\0'; + v[2][256] = '\0'; + + zl = ziplistNew(); + for (i = 0; i < (sizeof(v)/sizeof(v[0])); i++) { + zl = ziplistPush(zl, (unsigned char *) v[i], strlen(v[i]), ZIPLIST_TAIL); + } + + verify(zl, e); + + assert(e[0].prevrawlensize == 1); + assert(e[1].prevrawlensize == 5); + assert(e[2].prevrawlensize == 1); + + /* Deleting entry 1 will increase `prevrawlensize` for entry 2 */ + unsigned char *p = e[1].p; + zl = ziplistDelete(zl, &p); + + verify(zl, e); + + assert(e[0].prevrawlensize == 1); + assert(e[1].prevrawlensize == 5); + + printf("SUCCESS\n\n"); + } + printf("Create long list and check indices:\n"); { zl = ziplistNew(); @@ -1173,50 +1417,77 @@ int main(int argc, char **argv) { printf("Stress with random payloads of different encoding:\n"); { - int i, idx, where, len; - long long v; + int i,j,len,where; unsigned char *p; - char buf[0x4041]; /* max length of generated string */ - zl = ziplistNew(); - for (i = 0; i < 100000; i++) { - where = (rand() & 1) ? ZIPLIST_HEAD : ZIPLIST_TAIL; - if (rand() & 1) { - /* equally likely create a 16, 32 or 64 bit int */ - v = (rand() & INT16_MAX) + ((1ll << 32) >> ((rand() % 3)*16)); - v *= 2*(rand() & 1)-1; /* randomly flip sign */ - sprintf(buf, "%lld", v); - zl = ziplistPush(zl, (unsigned char*)buf, strlen(buf), where); - } else { - /* equally likely generate 6, 14 or >14 bit length */ - v = rand() & 0x3f; - v += 0x4000 >> ((rand() % 3)*8); - memset(buf, 'x', v); - zl = ziplistPush(zl, (unsigned char*)buf, v, where); - } + char buf[1024]; + int buflen; + list *ref; + listNode *refnode; + + /* Hold temp vars from ziplist */ + unsigned char *sstr; + unsigned int slen; + long long sval; + + for (i = 0; i < 20000; i++) { + zl = ziplistNew(); + ref = listCreate(); + listSetFreeMethod(ref,sdsfree); + len = rand() % 256; + + /* Create lists */ + for (j = 0; j < len; j++) { + where = (rand() & 1) ? ZIPLIST_HEAD : ZIPLIST_TAIL; + if (rand() % 2) { + buflen = randstring(buf,1,sizeof(buf)-1); + } else { + switch(rand() % 3) { + case 0: + buflen = sprintf(buf,"%lld",(0LL + rand()) >> 20); + break; + case 1: + buflen = sprintf(buf,"%lld",(0LL + rand())); + break; + case 2: + buflen = sprintf(buf,"%lld",(0LL + rand()) << 20); + break; + default: + assert(NULL); + } + } - /* delete a random element */ - if ((len = ziplistLen(zl)) >= 10) { - idx = rand() % len; - // printf("Delete index %d\n", idx); - // ziplistRepr(zl); - ziplistDeleteRange(zl, idx, 1); - // ziplistRepr(zl); - len--; + /* Add to ziplist */ + zl = ziplistPush(zl, (unsigned char*)buf, buflen, where); + + /* Add to reference list */ + if (where == ZIPLIST_HEAD) { + listAddNodeHead(ref,sdsnewlen(buf, buflen)); + } else if (where == ZIPLIST_TAIL) { + listAddNodeTail(ref,sdsnewlen(buf, buflen)); + } else { + assert(NULL); + } } - /* iterate from front to back */ - idx = 0; - p = ziplistIndex(zl, 0); - while((p = ziplistNext(zl,p))) - idx++; - assert(len == idx+1); - - /* iterate from back to front */ - idx = 0; - p = ziplistIndex(zl, -1); - while((p = ziplistPrev(zl,p))) - idx++; - assert(len == idx+1); + assert(listLength(ref) == ziplistLen(zl)); + for (j = 0; j < len; j++) { + /* Naive way to get elements, but similar to the stresser + * executed from the Tcl test suite. */ + p = ziplistIndex(zl,j); + refnode = listIndex(ref,j); + + assert(ziplistGet(p,&sstr,&slen,&sval)); + if (sstr == NULL) { + buflen = sprintf(buf,"%lld",sval); + } else { + buflen = slen; + memcpy(buf,sstr,buflen); + buf[buflen] = '\0'; + } + assert(memcmp(buf,listNodeValue(refnode),buflen) == 0); + } + zfree(zl); + listRelease(ref); } printf("SUCCESS\n\n"); }