diff options
Diffstat (limited to 'contrib/cdb/cdb_init.c')
| -rw-r--r-- | contrib/cdb/cdb_init.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/contrib/cdb/cdb_init.c b/contrib/cdb/cdb_init.c new file mode 100644 index 0000000..bfc6dd0 --- /dev/null +++ b/contrib/cdb/cdb_init.c @@ -0,0 +1,140 @@ +/* $Id: cdb_init.c,v 1.12 2008-11-06 18:07:04 mjt Exp $ + * cdb_init, cdb_free and cdb_read routines + * + * This file is a part of tinycdb package by Michael Tokarev, mjt@corpit.ru. + * Public domain. + */ + +#include "cdb.h" + +unsigned +cdb_hash(const void *buf, unsigned len) +{ + register const unsigned char *p = (const unsigned char *) buf; + register const unsigned char *end = p + len; + register unsigned hash = 5381; /* start value */ + while (p < end) + hash = (hash + (hash << 5)) ^ *p++; + return hash; +} + +int +cdb_init(struct cdb *cdbp, int fd) +{ + struct stat st; + unsigned char *mem; + unsigned fsize, dend; +#ifdef _WIN32 + HANDLE hFile, hMapping; +#endif + + /* get file size */ + if (fstat (fd, &st) < 0) + return -1; + /* trivial sanity check: at least toc should be here */ + if (st.st_size < 2048) + return errno = EPROTO, -1; + fsize = (unsigned) (st.st_size & 0xffffffffu); + /* memory-map file */ +#ifdef _WIN32 + hFile = (HANDLE) _get_osfhandle(fd); + if (hFile == (HANDLE) -1) + return -1; + hMapping = CreateFileMapping(hFile, NULL, PAGE_READONLY, 0, 0, NULL); + if (!hMapping) + return -1; + mem = (unsigned char *)MapViewOfFile(hMapping, FILE_MAP_READ, 0, 0, 0); + CloseHandle(hMapping); + if (!mem) + return -1; +#else + mem = (unsigned char*) mmap (NULL, fsize, PROT_READ, MAP_SHARED, fd, 0); + if (mem == MAP_FAILED) + return -1; +#endif /* _WIN32 */ + + cdbp->cdb_fd = fd; + cdbp->cdb_fsize = fsize; + cdbp->cdb_mem = mem; + cdbp->mtime = st.st_mtime; + + cdbp->cdb_vpos = cdbp->cdb_vlen = 0; + cdbp->cdb_kpos = cdbp->cdb_klen = 0; + dend = cdb_unpack (mem); + if (dend < 2048) + dend = 2048; + else if (dend >= fsize) + dend = fsize; + cdbp->cdb_dend = dend; + + return 0; +} + +void +cdb_free(struct cdb *cdbp) +{ + if (cdbp->cdb_mem) { +#ifdef _WIN32 + UnmapViewOfFile((void*) cdbp->cdb_mem); +#else + munmap ((void*) cdbp->cdb_mem, cdbp->cdb_fsize); +#endif /* _WIN32 */ + cdbp->cdb_mem = NULL; + } + cdbp->cdb_fsize = 0; + + if (cdbp->loop) { + ev_stat_stop (cdbp->loop, &cdbp->stat_ev); + } +} + +const void * +cdb_get(const struct cdb *cdbp, unsigned len, unsigned pos) +{ + if (pos > cdbp->cdb_fsize || cdbp->cdb_fsize - pos < len) { + errno = EPROTO; + return NULL; + } + return cdbp->cdb_mem + pos; +} + +int +cdb_read(const struct cdb *cdbp, void *buf, unsigned len, unsigned pos) +{ + const void *data = cdb_get (cdbp, len, pos); + if (!data) + return -1; + memcpy (buf, data, len); + return 0; +} + +static void +cdb_timer_callback (EV_P_ ev_stat *w, int revents) +{ + struct cdb *cdbp = w->data; + gint nfd; + + /* Check cdb file for modifications */ + if ((nfd = open (cdbp->filename, O_RDONLY)) != -1) { + if (cdbp->cdb_mem) { +#ifdef _WIN32 + UnmapViewOfFile((void*) cdbp->cdb_mem); +#else + munmap ((void*) cdbp->cdb_mem, cdbp->cdb_fsize); +#endif /* _WIN32 */ + cdbp->cdb_mem = NULL; + } + (void)close (cdbp->cdb_fd); + cdbp->cdb_fsize = 0; + (void)cdb_init (cdbp, nfd); + } +} + +void +cdb_add_timer (struct cdb *cdbp, EV_P_ ev_tstamp seconds) +{ + cdbp->loop = loop; + ev_stat_init (&cdbp->stat_ev, cdb_timer_callback, cdbp->filename, seconds); + cdbp->stat_ev.data = cdbp; + ev_stat_start (EV_A_ &cdbp->stat_ev); +} |