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author | Federico Ceratto <federico.ceratto@gmail.com> | 2016-03-30 21:40:42 +0000 |
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committer | Federico Ceratto <federico.ceratto@gmail.com> | 2016-03-30 21:40:42 +0000 |
commit | 9ce153ce7167c11adba8ac225edc7a707e97c6eb (patch) | |
tree | 9f6e849cce2dcc7e5b4e9e6252c843dc2d0787a2 /src/common.c | |
download | netdata-9ce153ce7167c11adba8ac225edc7a707e97c6eb.tar.xz netdata-9ce153ce7167c11adba8ac225edc7a707e97c6eb.zip |
Imported Upstream version 1.0.0upstream/1.0.0
Diffstat (limited to 'src/common.c')
-rwxr-xr-x | src/common.c | 226 |
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); +} + |