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authorFederico Ceratto <federico.ceratto@gmail.com>2016-03-30 21:40:42 +0000
committerFederico Ceratto <federico.ceratto@gmail.com>2016-03-30 21:40:42 +0000
commit9ce153ce7167c11adba8ac225edc7a707e97c6eb (patch)
tree9f6e849cce2dcc7e5b4e9e6252c843dc2d0787a2 /src/common.c
downloadnetdata-9ce153ce7167c11adba8ac225edc7a707e97c6eb.tar.xz
netdata-9ce153ce7167c11adba8ac225edc7a707e97c6eb.zip
Imported Upstream version 1.0.0upstream/1.0.0
Diffstat (limited to 'src/common.c')
-rwxr-xr-xsrc/common.c226
1 files changed, 226 insertions, 0 deletions
diff --git a/src/common.c b/src/common.c
new file mode 100755
index 000000000..e3c3afe3f
--- /dev/null
+++ b/src/common.c
@@ -0,0 +1,226 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <sys/syscall.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+
+#include "log.h"
+#include "common.h"
+#include "appconfig.h"
+
+char *global_host_prefix = "";
+int enable_ksm = 1;
+
+/*
+// http://stackoverflow.com/questions/7666509/hash-function-for-string
+uint32_t simple_hash(const char *name)
+{
+ const char *s = name;
+ uint32_t hash = 5381;
+ int i;
+
+ while((i = *s++)) hash = ((hash << 5) + hash) + i;
+
+ // fprintf(stderr, "HASH: %lu %s\n", hash, name);
+
+ return hash;
+}
+*/
+
+
+// http://isthe.com/chongo/tech/comp/fnv/#FNV-1a
+uint32_t simple_hash(const char *name) {
+ unsigned char *s = (unsigned char *)name;
+ uint32_t hval = 0x811c9dc5;
+
+ // 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);
+
+ // xor the bottom with the current octet
+ hval ^= (uint32_t)*s++;
+ }
+
+ // fprintf(stderr, "HASH: %u = %s\n", hval, name);
+ return hval;
+}
+
+/*
+// http://eternallyconfuzzled.com/tuts/algorithms/jsw_tut_hashing.aspx
+// one at a time hash
+uint32_t simple_hash(const char *name) {
+ unsigned char *s = (unsigned char *)name;
+ uint32_t h = 0;
+
+ while(*s) {
+ h += *s++;
+ h += (h << 10);
+ h ^= (h >> 6);
+ }
+
+ h += (h << 3);
+ h ^= (h >> 11);
+ h += (h << 15);
+
+ // fprintf(stderr, "HASH: %u = %s\n", h, name);
+
+ return h;
+}
+*/
+
+void strreverse(char* begin, char* end)
+{
+ char aux;
+ while (end > begin)
+ aux = *end, *end-- = *begin, *begin++ = aux;
+}
+
+char *mystrsep(char **ptr, char *s)
+{
+ char *p = "";
+ while ( p && !p[0] && *ptr ) p = strsep(ptr, s);
+ return(p);
+}
+
+char *trim(char *s)
+{
+ // skip leading spaces
+ 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--;
+ }
+ if(c < 0) return NULL;
+ if(!*s) return NULL;
+ return s;
+}
+
+void *mymmap(const char *filename, size_t size, int flags, int ksm)
+{
+ int fd;
+ void *mem = NULL;
+
+ errno = 0;
+ fd = open(filename, O_RDWR|O_CREAT|O_NOATIME, 0664);
+ if(fd != -1) {
+ if(lseek(fd, size, SEEK_SET) == (long)size) {
+ if(write(fd, "", 1) == 1) {
+ if(ftruncate(fd, size))
+ error("Cannot truncate file '%s' to size %ld. Will use the larger file.", filename, size);
+
+#ifdef MADV_MERGEABLE
+ if(flags & MAP_SHARED || !enable_ksm || !ksm) {
+#endif
+ mem = mmap(NULL, size, PROT_READ|PROT_WRITE, flags, fd, 0);
+ if(mem) {
+ int advise = MADV_SEQUENTIAL|MADV_DONTFORK;
+ if(flags & MAP_SHARED) advise |= MADV_WILLNEED;
+
+ if(madvise(mem, size, advise) != 0)
+ error("Cannot advise the kernel about the memory usage of file '%s'.", filename);
+ }
+#ifdef MADV_MERGEABLE
+ }
+ else {
+ mem = mmap(NULL, size, PROT_READ|PROT_WRITE, flags|MAP_ANONYMOUS, -1, 0);
+ if(mem) {
+ if(lseek(fd, 0, SEEK_SET) == 0) {
+ if(read(fd, mem, size) != (ssize_t)size)
+ error("Cannot read from file '%s'", filename);
+ }
+ else
+ error("Cannot seek to beginning of file '%s'.", filename);
+
+ // don't use MADV_SEQUENTIAL|MADV_DONTFORK, they disable MADV_MERGEABLE
+ if(madvise(mem, size, MADV_SEQUENTIAL|MADV_DONTFORK) != 0)
+ error("Cannot advise the kernel about the memory usage (MADV_SEQUENTIAL|MADV_DONTFORK) of file '%s'.", filename);
+
+ if(madvise(mem, size, MADV_MERGEABLE) != 0)
+ error("Cannot advise the kernel about the memory usage (MADV_MERGEABLE) of file '%s'.", filename);
+ }
+ else
+ error("Cannot allocate PRIVATE ANONYMOUS memory for KSM for file '%s'.", filename);
+ }
+#endif
+ }
+ else error("Cannot write to file '%s' at position %ld.", filename, size);
+ }
+ else error("Cannot seek file '%s' to size %ld.", filename, size);
+
+ close(fd);
+ }
+ else error("Cannot create/open file '%s'.", filename);
+
+ return mem;
+}
+
+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());
+
+ int fd = open(tmpfilename, O_RDWR|O_CREAT|O_NOATIME, 0664);
+ if(fd < 0) {
+ error("Cannot create/open file '%s'.", filename);
+ return -1;
+ }
+
+ if(write(fd, mem, size) != (long)size) {
+ error("Cannot write to file '%s' %ld bytes.", filename, (long)size);
+ close(fd);
+ return -1;
+ }
+
+ close(fd);
+
+ int ret = 0;
+ if(rename(tmpfilename, filename)) {
+ error("Cannot rename '%s' to '%s'", tmpfilename, filename);
+ ret = -1;
+ }
+
+ return ret;
+}
+
+int fd_is_valid(int fd) {
+ return fcntl(fd, F_GETFD) != -1 || errno != EBADF;
+}
+
+/*
+ ***************************************************************************
+ * Get number of clock ticks per second.
+ ***************************************************************************
+ */
+unsigned int hz;
+
+void get_HZ(void)
+{
+ long ticks;
+
+ if ((ticks = sysconf(_SC_CLK_TCK)) == -1) {
+ perror("sysconf");
+ }
+
+ hz = (unsigned int) ticks;
+}
+
+pid_t gettid(void)
+{
+ return syscall(SYS_gettid);
+}
+