唯快不破:redis源码剖析04-sds动态字符串
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阅读完redis动态字符串封装最大的一个感悟就是封装的优美,在原有char *字符串基础上添加了字符串头部元信息,这样既方便了字符串的管理,又不失原有的使用方便性。并且充分调用了c底层api高效进行字符串操作,基于内存级别的字符串操作。还有就是sds动态字符串会根据字符串长度的变化自动选择头部元信息类型,当现有空间不足时,在1M前都是成倍增长空间,大于1M情况下是增长1M,这样避免了频繁扩充空间。
sds.h
/* SDSLib 2.0 -- A C dynamic strings library * * Copyright (c) 2006-2015, Salvatore Sanfilippo <antirez at gmail dot com> * Copyright (c) 2015, Oran Agra * Copyright (c) 2015, Redis Labs, Inc * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of Redis nor the names of its contributors may be used * to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */#ifndef __SDS_H#define __SDS_H/*成倍增长的限值,小于此值前空间不够时成被扩充空间*/#define SDS_MAX_PREALLOC (1024*1024)#include <sys/types.h>#include <stdarg.h>#include <stdint.h>/*动态字符串类型其实就是char类型的指针*/typedef char *sds;/* Note: sdshdr5 is never used, we just access the flags byte directly. * However is here to document the layout of type 5 SDS strings. *//*已废弃*/struct __attribute__ ((__packed__)) sdshdr5 { unsigned char flags; /* 3 lsb of type, and 5 msb of string length */ char buf[];};struct __attribute__ ((__packed__)) sdshdr8 { uint8_t len; /* used */ uint8_t alloc; /* excluding the header and null terminator */ unsigned char flags; /* 3 lsb of type, 5 unused bits */ char buf[];};struct __attribute__ ((__packed__)) sdshdr16 { uint16_t len; /* used */ uint16_t alloc; /* excluding the header and null terminator */ unsigned char flags; /* 3 lsb of type, 5 unused bits */ char buf[];};struct __attribute__ ((__packed__)) sdshdr32 { uint32_t len; /* used */ uint32_t alloc; /* excluding the header and null terminator */ unsigned char flags; /* 3 lsb of type, 5 unused bits */ char buf[];};/*__attribute__ ((__packed__))表示取消系统自动对齐,结构体大小为各字段之和*//*动态字符串头部结构体类型,用于记录动态字符串信息*/struct __attribute__ ((__packed__)) sdshdr64 { /*uint64_t是stdint标准库中定长的数据类型,不随平台变化*/ /*字符串长度*/ uint64_t len; /* used */ /*总申请的字符串空间大小,不包括头结构体和终止符*/ uint64_t alloc; /* excluding the header and null terminator */ /*前三位表示动态字符串类型,后五位未使用*/ unsigned char flags; /* 3 lsb of type, 5 unused bits */ /*实际字符串存储空间*/ char buf[];};#define SDS_TYPE_5 0#define SDS_TYPE_8 1#define SDS_TYPE_16 2#define SDS_TYPE_32 3#define SDS_TYPE_64 4#define SDS_TYPE_MASK 7#define SDS_TYPE_BITS 3/*##起连接作用*//*取得动态字符串头并赋值给sh*/#define SDS_HDR_VAR(T,s) struct sdshdr##T *sh = (void*)((s)-(sizeof(struct sdshdr##T)));/*取得动态字符串头*/#define SDS_HDR(T,s) ((struct sdshdr##T *)((s)-(sizeof(struct sdshdr##T))))#define SDS_TYPE_5_LEN(f) ((f)>>SDS_TYPE_BITS)/*C99标准中支持了inline内联*//*取得动态字符串长度*/static inline size_t sdslen(const sds s) { /*buf前一个字节就是类型标志*/ unsigned char flags = s[-1]; switch(flags&SDS_TYPE_MASK) { case SDS_TYPE_5: return SDS_TYPE_5_LEN(flags); case SDS_TYPE_8: return SDS_HDR(8,s)->len; case SDS_TYPE_16: return SDS_HDR(16,s)->len; case SDS_TYPE_32: return SDS_HDR(32,s)->len; case SDS_TYPE_64: return SDS_HDR(64,s)->len; } return 0;}/*计算动态字符串可用空间*/static inline size_t sdsavail(const sds s) { unsigned char flags = s[-1]; switch(flags&SDS_TYPE_MASK) { case SDS_TYPE_5: { return 0; } case SDS_TYPE_8: { SDS_HDR_VAR(8,s); return sh->alloc - sh->len; } case SDS_TYPE_16: { SDS_HDR_VAR(16,s); return sh->alloc - sh->len; } case SDS_TYPE_32: { SDS_HDR_VAR(32,s); return sh->alloc - sh->len; } case SDS_TYPE_64: { SDS_HDR_VAR(64,s); return sh->alloc - sh->len; } } return 0;}/*设置动态字符串长度头结构体属性*/static inline void sdssetlen(sds s, size_t newlen) { unsigned char flags = s[-1]; switch(flags&SDS_TYPE_MASK) { case SDS_TYPE_5: { unsigned char *fp = ((unsigned char*)s)-1; *fp = SDS_TYPE_5 | (newlen << SDS_TYPE_BITS); } break; case SDS_TYPE_8: SDS_HDR(8,s)->len = newlen; break; case SDS_TYPE_16: SDS_HDR(16,s)->len = newlen; break; case SDS_TYPE_32: SDS_HDR(32,s)->len = newlen; break; case SDS_TYPE_64: SDS_HDR(64,s)->len = newlen; break; }}/*增加动态字符串长度属性值*/static inline void sdsinclen(sds s, size_t inc) { unsigned char flags = s[-1]; switch(flags&SDS_TYPE_MASK) { case SDS_TYPE_5: { unsigned char *fp = ((unsigned char*)s)-1; unsigned char newlen = SDS_TYPE_5_LEN(flags)+inc; *fp = SDS_TYPE_5 | (newlen << SDS_TYPE_BITS); } break; case SDS_TYPE_8: SDS_HDR(8,s)->len += inc; break; case SDS_TYPE_16: SDS_HDR(16,s)->len += inc; break; case SDS_TYPE_32: SDS_HDR(32,s)->len += inc; break; case SDS_TYPE_64: SDS_HDR(64,s)->len += inc; break; }}/*取得动态字符串分配空间大小属性值*//* sdsalloc() = sdsavail() + sdslen() */static inline size_t sdsalloc(const sds s) { unsigned char flags = s[-1]; switch(flags&SDS_TYPE_MASK) { case SDS_TYPE_5: return SDS_TYPE_5_LEN(flags); case SDS_TYPE_8: return SDS_HDR(8,s)->alloc; case SDS_TYPE_16: return SDS_HDR(16,s)->alloc; case SDS_TYPE_32: return SDS_HDR(32,s)->alloc; case SDS_TYPE_64: return SDS_HDR(64,s)->alloc; } return 0;}/*设置动态字符串分配空间大小属性值*/static inline void sdssetalloc(sds s, size_t newlen) { unsigned char flags = s[-1]; switch(flags&SDS_TYPE_MASK) { case SDS_TYPE_5: /* Nothing to do, this type has no total allocation info. */ break; case SDS_TYPE_8: SDS_HDR(8,s)->alloc = newlen; break; case SDS_TYPE_16: SDS_HDR(16,s)->alloc = newlen; break; case SDS_TYPE_32: SDS_HDR(32,s)->alloc = newlen; break; case SDS_TYPE_64: SDS_HDR(64,s)->alloc = newlen; break; }}/*创建动态字符串并初始化字符串内容和长度*/sds sdsnewlen(const void *init, size_t initlen);/*创建动态字符串并初始化字符串内容*/sds sdsnew(const char *init);/*创建空的动态字符串*/sds sdsempty(void);/*复制动态字符串*/sds sdsdup(const sds s);/*释放动态字符串*/void sdsfree(sds s);/*增长指定长度*/sds sdsgrowzero(sds s, size_t len);/*连接指定长度普通字符串*/sds sdscatlen(sds s, const void *t, size_t len);/*连接普通字符串*/sds sdscat(sds s, const char *t);/*连接动态字符串*/sds sdscatsds(sds s, const sds t);/*拷贝普通字符串指定长度*/sds sdscpylen(sds s, const char *t, size_t len);/*拷贝普通字符串*/sds sdscpy(sds s, const char *t);/*格式化打印动态字符串*/sds sdscatvprintf(sds s, const char *fmt, va_list ap);#ifdef __GNUC__/*GUNC编译器*/sds sdscatprintf(sds s, const char *fmt, ...) /*__attribute__ format属性进行参数检查*/ __attribute__((format(printf, 2, 3)));#elsesds sdscatprintf(sds s, const char *fmt, ...);#endif/*连接格式化字符串*/sds sdscatfmt(sds s, char const *fmt, ...);/*去掉两端空格*/sds sdstrim(sds s, const char *cset);/*取动态字符串指定范围内容*/void sdsrange(sds s, int start, int end);/*更新长度信息*/void sdsupdatelen(sds s);/*清空动态字符串*/void sdsclear(sds s);/*动态字符串相比较*/int sdscmp(const sds s1, const sds s2);/*将字符串拆分成多个动态字符串*/sds *sdssplitlen(const char *s, int len, const char *sep, int seplen, int *count);/*释放动态字符串*/void sdsfreesplitres(sds *tokens, int count);/*动态字符串转小写*/void sdstolower(sds s);/*动态字符串转大写*/void sdstoupper(sds s);/*long long构建动态字符串*/sds sdsfromlonglong(long long value);/*连接普通字符串*/sds sdscatrepr(sds s, const char *p, size_t len);/*拆分参数*/sds *sdssplitargs(const char *line, int *argc);/*映射字符*/sds sdsmapchars(sds s, const char *from, const char *to, size_t setlen);/*用指定分隔符连接参数*/sds sdsjoin(char **argv, int argc, char *sep);/*用指定分隔符连接动态字符串参数*/sds sdsjoinsds(sds *argv, int argc, const char *sep, size_t seplen);/* Low level functions exposed to the user API *//*确保腾出指定空间大小*/sds sdsMakeRoomFor(sds s, size_t addlen);/*增进长度*/void sdsIncrLen(sds s, int incr);/*去掉无效空格*/sds sdsRemoveFreeSpace(sds s);/*取得分配的空间大小*/size_t sdsAllocSize(sds s);/*动态字符串分配空间指针*/void *sdsAllocPtr(sds s);/* Export the allocator used by SDS to the program using SDS. * Sometimes the program SDS is linked to, may use a different set of * allocators, but may want to allocate or free things that SDS will * respectively free or allocate. */void *sds_malloc(size_t size);void *sds_realloc(void *ptr, size_t size);void sds_free(void *ptr);#ifdef REDIS_TESTint sdsTest(int argc, char *argv[]);#endif#endif
sds.c
/* SDSLib 2.0 -- A C dynamic strings library * * Copyright (c) 2006-2015, Salvatore Sanfilippo <antirez at gmail dot com> * Copyright (c) 2015, Oran Agra * Copyright (c) 2015, Redis Labs, Inc * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of Redis nor the names of its contributors may be used * to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */#include <stdio.h>#include <stdlib.h>#include <string.h>#include <ctype.h>#include <assert.h>#include <limits.h>#include "sds.h"#include "sdsalloc.h"/*计算动态字符串头部大小*/static inline int sdsHdrSize(char type) { switch(type&SDS_TYPE_MASK) { case SDS_TYPE_5: return sizeof(struct sdshdr5); case SDS_TYPE_8: return sizeof(struct sdshdr8); case SDS_TYPE_16: return sizeof(struct sdshdr16); case SDS_TYPE_32: return sizeof(struct sdshdr32); case SDS_TYPE_64: return sizeof(struct sdshdr64); } return 0;}/*动态字符串类型*/static inline char sdsReqType(size_t string_size) { if (string_size < 1<<5) return SDS_TYPE_5; if (string_size < 1<<8) return SDS_TYPE_8; if (string_size < 1<<16) return SDS_TYPE_16;#if (LONG_MAX == LLONG_MAX) if (string_size < 1ll<<32) return SDS_TYPE_32;#endif return SDS_TYPE_64;}/* Create a new sds string with the content specified by the 'init' pointer * and 'initlen'. * If NULL is used for 'init' the string is initialized with zero bytes. * * The string is always null-termined (all the sds strings are, always) so * even if you create an sds string with: * * mystring = sdsnewlen("abc",3); * * You can print the string with printf() as there is an implicit \0 at the * end of the string. However the string is binary safe and can contain * \0 characters in the middle, as the length is stored in the sds header. *//*创建指定大小动态字符串,并用指定内容初始化*/sds sdsnewlen(const void *init, size_t initlen) { void *sh; sds s; /*根据长度选择合适的动态字符串类型*/ char type = sdsReqType(initlen); /* Empty strings are usually created in order to append. Use type 8 * since type 5 is not good at this. */ /*SDS_TYPE_5已废弃*/ if (type == SDS_TYPE_5 && initlen == 0) type = SDS_TYPE_8; /*头部大小*/ int hdrlen = sdsHdrSize(type); unsigned char *fp; /* flags pointer. */ /*分配空间*/ sh = s_malloc(hdrlen+initlen+1); if (!init) /*没有指定初始化内容,全部字节置0*/ memset(sh, 0, hdrlen+initlen+1); if (sh == NULL) return NULL; s = (char*)sh+hdrlen; fp = ((unsigned char*)s)-1; switch(type) { case SDS_TYPE_5: { *fp = type | (initlen << SDS_TYPE_BITS); break; } case SDS_TYPE_8: { /*取得字符串头*/ SDS_HDR_VAR(8,s); sh->len = initlen; sh->alloc = initlen; *fp = type; break; } case SDS_TYPE_16: { SDS_HDR_VAR(16,s); sh->len = initlen; sh->alloc = initlen; *fp = type; break; } case SDS_TYPE_32: { SDS_HDR_VAR(32,s); sh->len = initlen; sh->alloc = initlen; *fp = type; break; } case SDS_TYPE_64: { SDS_HDR_VAR(64,s); sh->len = initlen; sh->alloc = initlen; *fp = type; break; } } if (initlen && init) /*复制初始化内容*/ memcpy(s, init, initlen); /*终结符*/ s[initlen] = '\0'; return s;}/* Create an empty (zero length) sds string. Even in this case the string * always has an implicit null term. *//*创建空的动态字符串*/sds sdsempty(void) { return sdsnewlen("",0);}/* Create a new sds string starting from a null terminated C string. *//*根据初始化内容创建动态字符串*/sds sdsnew(const char *init) { size_t initlen = (init == NULL) ? 0 : strlen(init); return sdsnewlen(init, initlen);}/* Duplicate an sds string. *//*复制动态字符串*/sds sdsdup(const sds s) { return sdsnewlen(s, sdslen(s));}/* Free an sds string. No operation is performed if 's' is NULL. *//*释放动态字符串*/void sdsfree(sds s) { if (s == NULL) return; s_free((char*)s-sdsHdrSize(s[-1]));}/* Set the sds string length to the length as obtained with strlen(), so * considering as content only up to the first null term character. * * This function is useful when the sds string is hacked manually in some * way, like in the following example: * * s = sdsnew("foobar"); * s[2] = '\0'; * sdsupdatelen(s); * printf("%d\n", sdslen(s)); * * The output will be "2", but if we comment out the call to sdsupdatelen() * the output will be "6" as the string was modified but the logical length * remains 6 bytes. *//*从新计算动态字符串长度*/void sdsupdatelen(sds s) { int reallen = strlen(s); sdssetlen(s, reallen);}/* Modify an sds string in-place to make it empty (zero length). * However all the existing buffer is not discarded but set as free space * so that next append operations will not require allocations up to the * number of bytes previously available. *//*清空动态字符串内容*/void sdsclear(sds s) { sdssetlen(s, 0); s[0] = '\0';}/* Enlarge the free space at the end of the sds string so that the caller * is sure that after calling this function can overwrite up to addlen * bytes after the end of the string, plus one more byte for nul term. * * Note: this does not change the *length* of the sds string as returned * by sdslen(), but only the free buffer space we have. *//*确保腾出指定空间大小*/sds sdsMakeRoomFor(sds s, size_t addlen) { void *sh, *newsh; /*可用空间*/ size_t avail = sdsavail(s); size_t len, newlen; char type, oldtype = s[-1] & SDS_TYPE_MASK; int hdrlen; /* Return ASAP if there is enough space left. */ /*现有的空间足够,直接返回*/ if (avail >= addlen) return s; len = sdslen(s); /*原始的空间*/ sh = (char*)s-sdsHdrSize(oldtype); /*新的长度*/ newlen = (len+addlen); if (newlen < SDS_MAX_PREALLOC) /*空间不够时成倍增长空间*/ newlen *= 2; else newlen += SDS_MAX_PREALLOC; type = sdsReqType(newlen); /* Don't use type 5: the user is appending to the string and type 5 is * not able to remember empty space, so sdsMakeRoomFor() must be called * at every appending operation. */ /*SDS_TYPE_5已废弃*/ if (type == SDS_TYPE_5) type = SDS_TYPE_8; hdrlen = sdsHdrSize(type); if (oldtype==type) { /*类型不变,在原有基础上重新分配*/ newsh = s_realloc(sh, hdrlen+newlen+1); if (newsh == NULL) return NULL; s = (char*)newsh+hdrlen; } else { /* Since the header size changes, need to move the string forward, * and can't use realloc */ /*类型有变,重新分配空间*/ newsh = s_malloc(hdrlen+newlen+1); if (newsh == NULL) return NULL; /*将原先内容拷贝到新的空间中*/ memcpy((char*)newsh+hdrlen, s, len+1); /*释放原先空间*/ s_free(sh); s = (char*)newsh+hdrlen; s[-1] = type; /*设置长度*/ sdssetlen(s, len); } /*重新设置分配空间的大小*/ sdssetalloc(s, newlen); return s;}/* Reallocate the sds string so that it has no free space at the end. The * contained string remains not altered, but next concatenation operations * will require a reallocation. * * After the call, the passed sds string is no longer valid and all the * references must be substituted with the new pointer returned by the call. *//*释放多余空间*/sds sdsRemoveFreeSpace(sds s) { void *sh, *newsh; char type, oldtype = s[-1] & SDS_TYPE_MASK; int hdrlen; size_t len = sdslen(s); sh = (char*)s-sdsHdrSize(oldtype); type = sdsReqType(len); hdrlen = sdsHdrSize(type); if (oldtype==type) { /*类型没变直接在原基础上重新分配空间*/ newsh = s_realloc(sh, hdrlen+len+1); if (newsh == NULL) return NULL; s = (char*)newsh+hdrlen; } else { /*类型变化需要重新分配空间*/ newsh = s_malloc(hdrlen+len+1); if (newsh == NULL) return NULL; /*将原先内容拷贝到新空间*/ memcpy((char*)newsh+hdrlen, s, len+1); /*释放原来的空间*/ s_free(sh); s = (char*)newsh+hdrlen; s[-1] = type; sdssetlen(s, len); } sdssetalloc(s, len); return s;}/* Return the total size of the allocation of the specifed sds string, * including: * 1) The sds header before the pointer. * 2) The string. * 3) The free buffer at the end if any. * 4) The implicit null term. *//*动态字符串总空间大小*/size_t sdsAllocSize(sds s) { size_t alloc = sdsalloc(s); return sdsHdrSize(s[-1])+alloc+1;}/* Return the pointer of the actual SDS allocation (normally SDS strings * are referenced by the start of the string buffer). *//*取得动态字符串分配的空间头地址*/void *sdsAllocPtr(sds s) { return (void*) (s-sdsHdrSize(s[-1]));}/* Increment the sds length and decrements the left free space at the * end of the string according to 'incr'. Also set the null term * in the new end of the string. * * This function is used in order to fix the string length after the * user calls sdsMakeRoomFor(), writes something after the end of * the current string, and finally needs to set the new length. * * Note: it is possible to use a negative increment in order to * right-trim the string. * * Usage example: * * Using sdsIncrLen() and sdsMakeRoomFor() it is possible to mount the * following schema, to cat bytes coming from the kernel to the end of an * sds string without copying into an intermediate buffer: * * oldlen = sdslen(s); * s = sdsMakeRoomFor(s, BUFFER_SIZE); * nread = read(fd, s+oldlen, BUFFER_SIZE); * ... check for nread <= 0 and handle it ... * sdsIncrLen(s, nread); *//*增加或减少动态字符串长度*/void sdsIncrLen(sds s, int incr) { unsigned char flags = s[-1]; size_t len; switch(flags&SDS_TYPE_MASK) { case SDS_TYPE_5: { unsigned char *fp = ((unsigned char*)s)-1; unsigned char oldlen = SDS_TYPE_5_LEN(flags); assert((incr > 0 && oldlen+incr < 32) || (incr < 0 && oldlen >= (unsigned int)(-incr))); *fp = SDS_TYPE_5 | ((oldlen+incr) << SDS_TYPE_BITS); len = oldlen+incr; break; } case SDS_TYPE_8: { SDS_HDR_VAR(8,s); assert((incr >= 0 && sh->alloc-sh->len >= incr) || (incr < 0 && sh->len >= (unsigned int)(-incr))); len = (sh->len += incr); break; } case SDS_TYPE_16: { SDS_HDR_VAR(16,s); /*空间够不够*/ assert((incr >= 0 && sh->alloc-sh->len >= incr) || (incr < 0 && sh->len >= (unsigned int)(-incr))); len = (sh->len += incr); break; } case SDS_TYPE_32: { SDS_HDR_VAR(32,s); assert((incr >= 0 && sh->alloc-sh->len >= (unsigned int)incr) || (incr < 0 && sh->len >= (unsigned int)(-incr))); len = (sh->len += incr); break; } case SDS_TYPE_64: { SDS_HDR_VAR(64,s); assert((incr >= 0 && sh->alloc-sh->len >= (uint64_t)incr) || (incr < 0 && sh->len >= (uint64_t)(-incr))); len = (sh->len += incr); break; } default: len = 0; /* Just to avoid compilation warnings. */ } s[len] = '\0';}/* Grow the sds to have the specified length. Bytes that were not part of * the original length of the sds will be set to zero. * * if the specified length is smaller than the current length, no operation * is performed. *//*如果大于当前长度则增长长度并增长部分初始化为0*/sds sdsgrowzero(sds s, size_t len) { size_t curlen = sdslen(s); if (len <= curlen) return s; s = sdsMakeRoomFor(s,len-curlen); if (s == NULL) return NULL; /* Make sure added region doesn't contain garbage */ memset(s+curlen,0,(len-curlen+1)); /* also set trailing \0 byte */ sdssetlen(s, len); return s;}/* Append the specified binary-safe string pointed by 't' of 'len' bytes to the * end of the specified sds string 's'. * * After the call, the passed sds string is no longer valid and all the * references must be substituted with the new pointer returned by the call. *//*连接指定长度的内容*/sds sdscatlen(sds s, const void *t, size_t len) { size_t curlen = sdslen(s); s = sdsMakeRoomFor(s,len); if (s == NULL) return NULL; memcpy(s+curlen, t, len); sdssetlen(s, curlen+len); s[curlen+len] = '\0'; return s;}/* Append the specified null termianted C string to the sds string 's'. * * After the call, the passed sds string is no longer valid and all the * references must be substituted with the new pointer returned by the call. *//*连接字符串*/sds sdscat(sds s, const char *t) { return sdscatlen(s, t, strlen(t));}/* Append the specified sds 't' to the existing sds 's'. * * After the call, the modified sds string is no longer valid and all the * references must be substituted with the new pointer returned by the call. *//*连接动态字符串*/sds sdscatsds(sds s, const sds t) { return sdscatlen(s, t, sdslen(t));}/* Destructively modify the sds string 's' to hold the specified binary * safe string pointed by 't' of length 'len' bytes. *//*拷贝指定长度内容到动态字符串*/sds sdscpylen(sds s, const char *t, size_t len) { if (sdsalloc(s) < len) { /*已有空间不够时重新分配空间*/ s = sdsMakeRoomFor(s,len-sdslen(s)); if (s == NULL) return NULL; } /*拷贝内容*/ memcpy(s, t, len); s[len] = '\0'; sdssetlen(s, len); return s;}/* Like sdscpylen() but 't' must be a null-termined string so that the length * of the string is obtained with strlen(). *//*拷贝字符串*/sds sdscpy(sds s, const char *t) { return sdscpylen(s, t, strlen(t));}/* Helper for sdscatlonglong() doing the actual number -> string * conversion. 's' must point to a string with room for at least * SDS_LLSTR_SIZE bytes. * * The function returns the length of the null-terminated string * representation stored at 's'. */#define SDS_LLSTR_SIZE 21/*long long转字符串*/int sdsll2str(char *s, long long value) { char *p, aux; unsigned long long v; size_t l; /* Generate the string representation, this method produces * an reversed string. */ v = (value < 0) ? -value : value; /*除10取余取每一位*/ p = s; do { *p++ = '0'+(v%10); v /= 10; } while(v); if (value < 0) *p++ = '-'; /* Compute length and add null term. */ l = p-s; *p = '\0'; /* Reverse the string. */ /*反转字符串*/ p--; while(s < p) { aux = *s; *s = *p; *p = aux; s++; p--; } /*返回数字字符串长度*/ return l;}/* Identical sdsll2str(), but for unsigned long long type. *//*非负long long类型转字符串*/int sdsull2str(char *s, unsigned long long v) { char *p, aux; size_t l; /* Generate the string representation, this method produces * an reversed string. */ p = s; do { *p++ = '0'+(v%10); v /= 10; } while(v); /* Compute length and add null term. */ l = p-s; *p = '\0'; /* Reverse the string. */ p--; while(s < p) { aux = *s; *s = *p; *p = aux; s++; p--; } return l;}/* Create an sds string from a long long value. It is much faster than: * * sdscatprintf(sdsempty(),"%lld\n", value); *//*从long long整数创建动态字符串*/sds sdsfromlonglong(long long value) { char buf[SDS_LLSTR_SIZE]; int len = sdsll2str(buf,value); return sdsnewlen(buf,len);}/* Like sdscatprintf() but gets va_list instead of being variadic. *//*格式化打印填充*/sds sdscatvprintf(sds s, const char *fmt, va_list ap) { va_list cpy; char staticbuf[1024], *buf = staticbuf, *t; size_t buflen = strlen(fmt)*2; /* We try to start using a static buffer for speed. * If not possible we revert to heap allocation. */ if (buflen > sizeof(staticbuf)) { buf = s_malloc(buflen); if (buf == NULL) return NULL; } else { buflen = sizeof(staticbuf); } /* Try with buffers two times bigger every time we fail to * fit the string in the current buffer size. */ while(1) { buf[buflen-2] = '\0'; va_copy(cpy,ap); vsnprintf(buf, buflen, fmt, cpy); va_end(cpy); if (buf[buflen-2] != '\0') { if (buf != staticbuf) s_free(buf); buflen *= 2; buf = s_malloc(buflen); if (buf == NULL) return NULL; continue; } break; } /* Finally concat the obtained string to the SDS string and return it. */ t = sdscat(s, buf); if (buf != staticbuf) s_free(buf); return t;}/* Append to the sds string 's' a string obtained using printf-alike format * specifier. * * After the call, the modified sds string is no longer valid and all the * references must be substituted with the new pointer returned by the call. * * Example: * * s = sdsnew("Sum is: "); * s = sdscatprintf(s,"%d+%d = %d",a,b,a+b). * * Often you need to create a string from scratch with the printf-alike * format. When this is the need, just use sdsempty() as the target string: * * s = sdscatprintf(sdsempty(), "... your format ...", args); *//*格式化填充*/sds sdscatprintf(sds s, const char *fmt, ...) { va_list ap; char *t; va_start(ap, fmt); t = sdscatvprintf(s,fmt,ap); va_end(ap); return t;}/* This function is similar to sdscatprintf, but much faster as it does * not rely on sprintf() family functions implemented by the libc that * are often very slow. Moreover directly handling the sds string as * new data is concatenated provides a performance improvement. * * However this function only handles an incompatible subset of printf-alike * format specifiers: * * %s - C String * %S - SDS string * %i - signed int * %I - 64 bit signed integer (long long, int64_t) * %u - unsigned int * %U - 64 bit unsigned integer (unsigned long long, uint64_t) * %% - Verbatim "%" character. *//*格式化填充*/sds sdscatfmt(sds s, char const *fmt, ...) { size_t initlen = sdslen(s); const char *f = fmt; int i; va_list ap; va_start(ap,fmt); f = fmt; /* Next format specifier byte to process. */ i = initlen; /* Position of the next byte to write to dest str. */ while(*f) { char next, *str; size_t l; long long num; unsigned long long unum; /* Make sure there is always space for at least 1 char. */ if (sdsavail(s)==0) { s = sdsMakeRoomFor(s,1); } switch(*f) { case '%': next = *(f+1); f++; switch(next) { case 's': case 'S': str = va_arg(ap,char*); l = (next == 's') ? strlen(str) : sdslen(str); if (sdsavail(s) < l) { s = sdsMakeRoomFor(s,l); } memcpy(s+i,str,l); sdsinclen(s,l); i += l; break; case 'i': case 'I': if (next == 'i') num = va_arg(ap,int); else num = va_arg(ap,long long); { char buf[SDS_LLSTR_SIZE]; l = sdsll2str(buf,num); if (sdsavail(s) < l) { s = sdsMakeRoomFor(s,l); } memcpy(s+i,buf,l); sdsinclen(s,l); i += l; } break; case 'u': case 'U': if (next == 'u') unum = va_arg(ap,unsigned int); else unum = va_arg(ap,unsigned long long); { char buf[SDS_LLSTR_SIZE]; l = sdsull2str(buf,unum); if (sdsavail(s) < l) { s = sdsMakeRoomFor(s,l); } memcpy(s+i,buf,l); sdsinclen(s,l); i += l; } break; default: /* Handle %% and generally %<unknown>. */ s[i++] = next; sdsinclen(s,1); break; } break; default: s[i++] = *f; sdsinclen(s,1); break; } f++; } va_end(ap); /* Add null-term */ s[i] = '\0'; return s;}/* Remove the part of the string from left and from right composed just of * contiguous characters found in 'cset', that is a null terminted C string. * * After the call, the modified sds string is no longer valid and all the * references must be substituted with the new pointer returned by the call. * * Example: * * s = sdsnew("AA...AA.a.aa.aHelloWorld :::"); * s = sdstrim(s,"Aa. :"); * printf("%s\n", s); * * Output will be just "Hello World". *//*去掉动态字符串两端指定字符集中的字符*/sds sdstrim(sds s, const char *cset) { char *start, *end, *sp, *ep; size_t len; sp = start = s; ep = end = s+sdslen(s)-1; /*调用strchr在字符串中查找字符*/ while(sp <= end && strchr(cset, *sp)) sp++; while(ep > sp && strchr(cset, *ep)) ep--; len = (sp > ep) ? 0 : ((ep-sp)+1); if (s != sp) memmove(s, sp, len); s[len] = '\0'; sdssetlen(s,len); return s;}/* Turn the string into a smaller (or equal) string containing only the * substring specified by the 'start' and 'end' indexes. * * start and end can be negative, where -1 means the last character of the * string, -2 the penultimate character, and so forth. * * The interval is inclusive, so the start and end characters will be part * of the resulting string. * * The string is modified in-place. * * Example: * * s = sdsnew("Hello World"); * sdsrange(s,1,-1); => "ello World" *//*截取指定下标段*/void sdsrange(sds s, int start, int end) { size_t newlen, len = sdslen(s); if (len == 0) return; if (start < 0) { start = len+start; if (start < 0) start = 0; } if (end < 0) { end = len+end; if (end < 0) end = 0; } newlen = (start > end) ? 0 : (end-start)+1; if (newlen != 0) { if (start >= (signed)len) { newlen = 0; } else if (end >= (signed)len) { end = len-1; newlen = (start > end) ? 0 : (end-start)+1; } } else { start = 0; } /*调用memmove移动字符串*/ if (start && newlen) memmove(s, s+start, newlen); s[newlen] = 0; sdssetlen(s,newlen);}/* Apply tolower() to every character of the sds string 's'. *//*动态字符串转小写*/void sdstolower(sds s) { int len = sdslen(s), j; /*调用tolower将字符串中每个字符转小写*/ for (j = 0; j < len; j++) s[j] = tolower(s[j]);}/* Apply toupper() to every character of the sds string 's'. *//*动态字符串转大写*/void sdstoupper(sds s) { int len = sdslen(s), j; /*调用toupper将字符串每个字符转大写*/ for (j = 0; j < len; j++) s[j] = toupper(s[j]);}/* Compare two sds strings s1 and s2 with memcmp(). * * Return value: * * positive if s1 > s2. * negative if s1 < s2. * 0 if s1 and s2 are exactly the same binary string. * * If two strings share exactly the same prefix, but one of the two has * additional characters, the longer string is considered to be greater than * the smaller one. *//*动态字符串比较*/int sdscmp(const sds s1, const sds s2) { size_t l1, l2, minlen; int cmp; l1 = sdslen(s1); l2 = sdslen(s2); minlen = (l1 < l2) ? l1 : l2; /*调用memcmp进行字符串比较*/ cmp = memcmp(s1,s2,minlen); if (cmp == 0) return l1-l2; return cmp;}/* Split 's' with separator in 'sep'. An array * of sds strings is returned. *count will be set * by reference to the number of tokens returned. * * On out of memory, zero length string, zero length * separator, NULL is returned. * * Note that 'sep' is able to split a string using * a multi-character separator. For example * sdssplit("foo_-_bar","_-_"); will return two * elements "foo" and "bar". * * This version of the function is binary-safe but * requires length arguments. sdssplit() is just the * same function but for zero-terminated strings. *//*根据指定长度的分割字符串分割字符串到动态字符串集合中*/sds *sdssplitlen(const char *s, int len, const char *sep, int seplen, int *count) { int elements = 0, slots = 5, start = 0, j; sds *tokens; if (seplen < 1 || len < 0) return NULL; tokens = s_malloc(sizeof(sds)*slots); if (tokens == NULL) return NULL; if (len == 0) { *count = 0; return tokens; } for (j = 0; j < (len-(seplen-1)); j++) { /* make sure there is room for the next element and the final one */ /*确保接下来分割字符串和最后一个字符串有空间存储*/ if (slots < elements+2) { sds *newtokens; slots *= 2; newtokens = s_realloc(tokens,sizeof(sds)*slots); if (newtokens == NULL) goto cleanup; tokens = newtokens; } /* search the separator */ if ((seplen == 1 && *(s+j) == sep[0]) || (memcmp(s+j,sep,seplen) == 0)) { /*找到分割字符串*/ tokens[elements] = sdsnewlen(s+start,j-start); if (tokens[elements] == NULL) goto cleanup; elements++; start = j+seplen; j = j+seplen-1; /* skip the separator */ } } /* Add the final element. We are sure there is room in the tokens array. */ /*添加最后一部分到集合*/ tokens[elements] = sdsnewlen(s+start,len-start); if (tokens[elements] == NULL) goto cleanup; elements++; *count = elements; return tokens;cleanup: { int i; /*异常情况下清空已申请的内容空间*/ for (i = 0; i < elements; i++) sdsfree(tokens[i]); s_free(tokens); *count = 0; return NULL; }}/* Free the result returned by sdssplitlen(), or do nothing if 'tokens' is NULL. *//*释放sdssplitlen返回的动态字符串集合*/void sdsfreesplitres(sds *tokens, int count) { if (!tokens) return; while(count--) sdsfree(tokens[count]); s_free(tokens);}/* Append to the sds string "s" an escaped string representation where * all the non-printable characters (tested with isprint()) are turned into * escapes in the form "\n\r\a...." or "\x<hex-number>". * * After the call, the modified sds string is no longer valid and all the * references must be substituted with the new pointer returned by the call. *//*填充转义字符字符串*/sds sdscatrepr(sds s, const char *p, size_t len) { s = sdscatlen(s,"\"",1); while(len--) { switch(*p) { case '\\': case '"': s = sdscatprintf(s,"\\%c",*p); break; case '\n': s = sdscatlen(s,"\\n",2); break; case '\r': s = sdscatlen(s,"\\r",2); break; case '\t': s = sdscatlen(s,"\\t",2); break; case '\a': s = sdscatlen(s,"\\a",2); break; case '\b': s = sdscatlen(s,"\\b",2); break; default: if (isprint(*p)) s = sdscatprintf(s,"%c",*p); else s = sdscatprintf(s,"\\x%02x",(unsigned char)*p); break; } p++; } return sdscatlen(s,"\"",1);}/* Helper function for sdssplitargs() that returns non zero if 'c' * is a valid hex digit. *//*判断是否是16进制字符*/int is_hex_digit(char c) { return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F');}/* Helper function for sdssplitargs() that converts a hex digit into an * integer from 0 to 15 *//*16进制字符转整数*/int hex_digit_to_int(char c) { switch(c) { case '0': return 0; case '1': return 1; case '2': return 2; case '3': return 3; case '4': return 4; case '5': return 5; case '6': return 6; case '7': return 7; case '8': return 8; case '9': return 9; case 'a': case 'A': return 10; case 'b': case 'B': return 11; case 'c': case 'C': return 12; case 'd': case 'D': return 13; case 'e': case 'E': return 14; case 'f': case 'F': return 15; default: return 0; }}/* Split a line into arguments, where every argument can be in the * following programming-language REPL-alike form: * * foo bar "newline are supported\n" and "\xff\x00otherstuff" * * The number of arguments is stored into *argc, and an array * of sds is returned. * * The caller should free the resulting array of sds strings with * sdsfreesplitres(). * * Note that sdscatrepr() is able to convert back a string into * a quoted string in the same format sdssplitargs() is able to parse. * * The function returns the allocated tokens on success, even when the * input string is empty, or NULL if the input contains unbalanced * quotes or closed quotes followed by non space characters * as in: "foo"bar or "foo' *//*分割一行字符串成参数*/sds *sdssplitargs(const char *line, int *argc) { const char *p = line; char *current = NULL; char **vector = NULL; *argc = 0; while(1) { /* skip blanks */ /*调用isspace跳过前部空格*/ while(*p && isspace(*p)) p++; if (*p) { /* get a token */ int inq=0; /* set to 1 if we are in "quotes" */ int insq=0; /* set to 1 if we are in 'single quotes' */ int done=0; /*创建一个空的动态字符串*/ if (current == NULL) current = sdsempty(); while(!done) { if (inq) { if (*p == '\\' && *(p+1) == 'x' && is_hex_digit(*(p+2)) && is_hex_digit(*(p+3))) { unsigned char byte; byte = (hex_digit_to_int(*(p+2))*16)+ hex_digit_to_int(*(p+3)); current = sdscatlen(current,(char*)&byte,1); p += 3; } else if (*p == '\\' && *(p+1)) { char c; p++; switch(*p) { case 'n': c = '\n'; break; case 'r': c = '\r'; break; case 't': c = '\t'; break; case 'b': c = '\b'; break; case 'a': c = '\a'; break; default: c = *p; break; } current = sdscatlen(current,&c,1); } else if (*p == '"') { /* closing quote must be followed by a space or * nothing at all. */ if (*(p+1) && !isspace(*(p+1))) goto err; done=1; } else if (!*p) { /* unterminated quotes */ goto err; } else { current = sdscatlen(current,p,1); } } else if (insq) { if (*p == '\\' && *(p+1) == '\'') { p++; current = sdscatlen(current,"'",1); } else if (*p == '\'') { /* closing quote must be followed by a space or * nothing at all. */ if (*(p+1) && !isspace(*(p+1))) goto err; done=1; } else if (!*p) { /* unterminated quotes */ goto err; } else { current = sdscatlen(current,p,1); } } else { switch(*p) { case ' ': case '\n': case '\r': case '\t': case '\0': done=1; break; case '"': inq=1; break; case '\'': insq=1; break; default: current = sdscatlen(current,p,1); break; } } if (*p) p++; } /* add the token to the vector */ /*将已解析的结果放入vector中*/ vector = s_realloc(vector,((*argc)+1)*sizeof(char*)); vector[*argc] = current; (*argc)++; current = NULL; } else { /* Even on empty input string return something not NULL. */ /*空字符串返回有一个void指针的集合*/ if (vector == NULL) vector = s_malloc(sizeof(void*)); return vector; } }err: /*异常情况下释放空间*/ while((*argc)--) sdsfree(vector[*argc]); s_free(vector); if (current) sdsfree(current); *argc = 0; return NULL;}/* Modify the string substituting all the occurrences of the set of * characters specified in the 'from' string to the corresponding character * in the 'to' array. * * For instance: sdsmapchars(mystring, "ho", "01", 2) * will have the effect of turning the string "hello" into "0ell1". * * The function returns the sds string pointer, that is always the same * as the input pointer since no resize is needed. *//*动态字符串字符映射*/sds sdsmapchars(sds s, const char *from, const char *to, size_t setlen) { size_t j, i, l = sdslen(s); for (j = 0; j < l; j++) { for (i = 0; i < setlen; i++) { if (s[j] == from[i]) { s[j] = to[i]; break; } } } return s;}/* Join an array of C strings using the specified separator (also a C string). * Returns the result as an sds string. *//*使用指定分隔符连接多个普通字符串为一个动态字符串*/sds sdsjoin(char **argv, int argc, char *sep) { sds join = sdsempty(); int j; for (j = 0; j < argc; j++) { join = sdscat(join, argv[j]); if (j != argc-1) join = sdscat(join,sep); } return join;}/* Like sdsjoin, but joins an array of SDS strings. *//*使用指定分隔符连接多个动态字符串为一个动态字符串*/sds sdsjoinsds(sds *argv, int argc, const char *sep, size_t seplen) { sds join = sdsempty(); int j; for (j = 0; j < argc; j++) { join = sdscatsds(join, argv[j]); if (j != argc-1) join = sdscatlen(join,sep,seplen); } return join;}/* Wrappers to the allocators used by SDS. Note that SDS will actually * just use the macros defined into sdsalloc.h in order to avoid to pay * the overhead of function calls. Here we define these wrappers only for * the programs SDS is linked to, if they want to touch the SDS internals * even if they use a different allocator. */void *sds_malloc(size_t size) { return s_malloc(size); }void *sds_realloc(void *ptr, size_t size) { return s_realloc(ptr,size); }void sds_free(void *ptr) { s_free(ptr); }#if defined(SDS_TEST_MAIN)#include <stdio.h>#include "testhelp.h"#include "limits.h"#define UNUSED(x) (void)(x)/*动态字符串测试函数*/int sdsTest(void) { { sds x = sdsnew("foo"), y; test_cond("Create a string and obtain the length", sdslen(x) == 3 && memcmp(x,"foo\0",4) == 0) sdsfree(x); x = sdsnewlen("foo",2); test_cond("Create a string with specified length", sdslen(x) == 2 && memcmp(x,"fo\0",3) == 0) x = sdscat(x,"bar"); test_cond("Strings concatenation", sdslen(x) == 5 && memcmp(x,"fobar\0",6) == 0); x = sdscpy(x,"a"); test_cond("sdscpy() against an originally longer string", sdslen(x) == 1 && memcmp(x,"a\0",2) == 0) x = sdscpy(x,"xyzxxxxxxxxxxyyyyyyyyyykkkkkkkkkk"); test_cond("sdscpy() against an originally shorter string", sdslen(x) == 33 && memcmp(x,"xyzxxxxxxxxxxyyyyyyyyyykkkkkkkkkk\0",33) == 0) sdsfree(x); x = sdscatprintf(sdsempty(),"%d",123); test_cond("sdscatprintf() seems working in the base case", sdslen(x) == 3 && memcmp(x,"123\0",4) == 0) sdsfree(x); x = sdsnew("--"); x = sdscatfmt(x, "Hello %s World %I,%I--", "Hi!", LLONG_MIN,LLONG_MAX); test_cond("sdscatfmt() seems working in the base case", sdslen(x) == 60 && memcmp(x,"--Hello Hi! World -9223372036854775808," "9223372036854775807--",60) == 0) printf("[%s]\n",x); sdsfree(x); x = sdsnew("--"); x = sdscatfmt(x, "%u,%U--", UINT_MAX, ULLONG_MAX); test_cond("sdscatfmt() seems working with unsigned numbers", sdslen(x) == 35 && memcmp(x,"--4294967295,18446744073709551615--",35) == 0) sdsfree(x); x = sdsnew(" x "); sdstrim(x," x"); test_cond("sdstrim() works when all chars match", sdslen(x) == 0) sdsfree(x); x = sdsnew(" x "); sdstrim(x," "); test_cond("sdstrim() works when a single char remains", sdslen(x) == 1 && x[0] == 'x') sdsfree(x); x = sdsnew("xxciaoyyy"); sdstrim(x,"xy"); test_cond("sdstrim() correctly trims characters", sdslen(x) == 4 && memcmp(x,"ciao\0",5) == 0) y = sdsdup(x); sdsrange(y,1,1); test_cond("sdsrange(...,1,1)", sdslen(y) == 1 && memcmp(y,"i\0",2) == 0) sdsfree(y); y = sdsdup(x); sdsrange(y,1,-1); test_cond("sdsrange(...,1,-1)", sdslen(y) == 3 && memcmp(y,"iao\0",4) == 0) sdsfree(y); y = sdsdup(x); sdsrange(y,-2,-1); test_cond("sdsrange(...,-2,-1)", sdslen(y) == 2 && memcmp(y,"ao\0",3) == 0) sdsfree(y); y = sdsdup(x); sdsrange(y,2,1); test_cond("sdsrange(...,2,1)", sdslen(y) == 0 && memcmp(y,"\0",1) == 0) sdsfree(y); y = sdsdup(x); sdsrange(y,1,100); test_cond("sdsrange(...,1,100)", sdslen(y) == 3 && memcmp(y,"iao\0",4) == 0) sdsfree(y); y = sdsdup(x); sdsrange(y,100,100); test_cond("sdsrange(...,100,100)", sdslen(y) == 0 && memcmp(y,"\0",1) == 0) sdsfree(y); sdsfree(x); x = sdsnew("foo"); y = sdsnew("foa"); test_cond("sdscmp(foo,foa)", sdscmp(x,y) > 0) sdsfree(y); sdsfree(x); x = sdsnew("bar"); y = sdsnew("bar"); test_cond("sdscmp(bar,bar)", sdscmp(x,y) == 0) sdsfree(y); sdsfree(x); x = sdsnew("aar"); y = sdsnew("bar"); test_cond("sdscmp(bar,bar)", sdscmp(x,y) < 0) sdsfree(y); sdsfree(x); x = sdsnewlen("\a\n\0foo\r",7); y = sdscatrepr(sdsempty(),x,sdslen(x)); test_cond("sdscatrepr(...data...)", memcmp(y,"\"\\a\\n\\x00foo\\r\"",15) == 0) { unsigned int oldfree; char *p; int step = 10, j, i; sdsfree(x); sdsfree(y); x = sdsnew("0"); test_cond("sdsnew() free/len buffers", sdslen(x) == 1 && sdsavail(x) == 0); /* Run the test a few times in order to hit the first two * SDS header types. */ for (i = 0; i < 10; i++) { int oldlen = sdslen(x); x = sdsMakeRoomFor(x,step); int type = x[-1]&SDS_TYPE_MASK; test_cond("sdsMakeRoomFor() len", sdslen(x) == oldlen); if (type != SDS_TYPE_5) { test_cond("sdsMakeRoomFor() free", sdsavail(x) >= step); oldfree = sdsavail(x); } p = x+oldlen; for (j = 0; j < step; j++) { p[j] = 'A'+j; } sdsIncrLen(x,step); } test_cond("sdsMakeRoomFor() content", memcmp("0ABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJABCDEFGHIJ",x,101) == 0); test_cond("sdsMakeRoomFor() final length",sdslen(x)==101); sdsfree(x); } } test_report() return 0;}#endif#ifdef SDS_TEST_MAINint main(void) { return sdsTest();}#endif
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