Merge remote-tracking branch 'fredericopissarra/changes' into registry

[netdata.git] / src / common.c

diff --git a/src/common.c b/src/common.c
index ca4b8753d23373931c75d7983b58155a8e9e970f..ea94ecc33baead4af53305c687ee01749dc96e45 100644 (file)
--- a/src/common.c
+++ b/src/common.c
@@ -582,8 +582,11 @@ uint32_t simple_hash(const char *name) {
        // FNV-1a algorithm
        while (*s) {
                // multiply by the 32 bit FNV magic prime mod 2^32
-               // gcc optimized
-               hval += (hval<<1) + (hval<<4) + (hval<<7) + (hval<<8) + (hval<<24);
+               // NOTE: No need to optimize with left shifts.
+               //       GCC will use imul instruction anyway.
+               //       Tested with 'gcc -O3 -S'
+               //hval += (hval<<1) + (hval<<4) + (hval<<7) + (hval<<8) + (hval<<24);
+               hval *= 16777619;
 
                // xor the bottom with the current octet
                hval ^= (uint32_t)*s++;
@@ -618,9 +621,15 @@ uint32_t simple_hash(const char *name) {
 
 void strreverse(char* begin, char* end)
 {
-    char aux;
-    while (end > begin)
-        aux = *end, *end-- = *begin, *begin++ = aux;
+       char aux;
+
+       while (end > begin)
+       {
+               // clearer code.
+               aux = *end;
+               *end-- = *begin;
+               *begin++ = aux;
+       }
 }
 
 char *mystrsep(char **ptr, char *s)
@@ -633,17 +642,22 @@ char *mystrsep(char **ptr, char *s)
 char *trim(char *s)
 {
        // skip leading spaces
+       // and 'comments' as well!?
        while(*s && isspace(*s)) s++;
        if(!*s || *s == '#') return NULL;
 
        // skip tailing spaces
-       long c = (long) strlen(s) - 1;
-       while(c >= 0 && isspace(s[c])) {
-               s[c] = '\0';
-               c--;
+       // this way is way faster. Writes only one NUL char.
+       ssize_t l = strlen(s);
+  if (--l >= 0)
+       {
+               char *p = s + l;
+               while (p > s && isspace(*p)) p--;
+               *++p = '\0';
        }
-       if(c < 0) return NULL;
+
        if(!*s) return NULL;
+
        return s;
 }
 
@@ -710,7 +724,7 @@ int savememory(const char *filename, void *mem, unsigned long size)
 {
        char tmpfilename[FILENAME_MAX + 1];
 
-       snprintf(tmpfilename, FILENAME_MAX, "%s.%ld.tmp", filename, (long)getpid());
+       snprintfz(tmpfilename, FILENAME_MAX, "%s.%ld.tmp", filename, (long)getpid());
 
        int fd = open(tmpfilename, O_RDWR|O_CREAT|O_NOATIME, 0664);
        if(fd < 0) {
@@ -782,3 +796,31 @@ char *fgets_trim_len(char *buf, size_t buf_size, FILE *fp, size_t *len) {
        return s;
 }
 
+char *strncpyz(char *dest, const char *src, size_t n)
+{
+  char *p = dest;
+
+       while (*src && n--)
+               *dest++ = *src++;
+  *dest = '\0';
+
+       return p;
+}
+
+int vsnprintfz(char *sout, size_t n, const char *fmt, va_list args)
+{
+       int size;
+
+  size = vsnprintf(sout, n, fmt, args);
+  sout[size] = '\0';
+  return size;
+}
+
+int snprintfz(char *sout, size_t n, const char *fmt, ...)
+{
+       va_list args;
+
+       va_start(args, fmt);
+       return vsnprintfz(sout, n, fmt, args);
+  // args will vanish!
+}