漫话Redis源码之二十七

这里的函数比较简单，snprintf的用法要学一下，别搞出边界问题啦。

#include <string.h>
#include <stdio.h>
 
#include "release.h"
#include "version.h"
#include "crc64.h"
 
char *redisGitSHA1(void) {
    return REDIS_GIT_SHA1;
}
 
char *redisGitDirty(void) {
    return REDIS_GIT_DIRTY;
}
 
uint64_t redisBuildId(void) {
    char *buildid = REDIS_VERSION REDIS_BUILD_ID REDIS_GIT_DIRTY REDIS_GIT_SHA1;
 
    return crc64(0,(unsigned char*)buildid,strlen(buildid));
}
 
/* Return a cached value of the build string in order to avoid recomputing
 * and converting it in hex every time: this string is shown in the INFO
 * output that should be fast. */
char *redisBuildIdString(void) {
    static char buf[32];
    static int cached = 0;
    if (!cached) {
        snprintf(buf,sizeof(buf),"%llx",(unsigned long long) redisBuildId());
        cached = 1;
    }
    return buf;
}