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author | Henryk Plötz <henryk@ploetzli.ch> | 2014-10-03 19:58:52 +0200 |
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committer | Henryk Plötz <henryk@ploetzli.ch> | 2014-10-03 19:58:52 +0200 |
commit | 0e5b2871ca6456b01d4bf037a6e68badf1ff1a41 (patch) | |
tree | 97b95b74c9618d85da9aa9451a55a819cd7b1c2e /cdb.c | |
download | tinydnssec-0e5b2871ca6456b01d4bf037a6e68badf1ff1a41.tar.gz tinydnssec-0e5b2871ca6456b01d4bf037a6e68badf1ff1a41.tar.bz2 |
Initial commit of djbdns-1.05.tar.gz
Source was http://cr.yp.to/djbdns/djbdns-1.05.tar.gz, SHA1 2efdb3a039d0c548f40936aa9cb30829e0ce8c3d
Diffstat (limited to 'cdb.c')
-rw-r--r-- | cdb.c | 136 |
1 files changed, 136 insertions, 0 deletions
@@ -0,0 +1,136 @@ +/* Public domain. */ + +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/mman.h> +#include <unistd.h> +#include "error.h" +#include "seek.h" +#include "byte.h" +#include "cdb.h" + +void cdb_free(struct cdb *c) +{ + if (c->map) { + munmap(c->map,c->size); + c->map = 0; + } +} + +void cdb_findstart(struct cdb *c) +{ + c->loop = 0; +} + +void cdb_init(struct cdb *c,int fd) +{ + struct stat st; + char *x; + + cdb_free(c); + cdb_findstart(c); + c->fd = fd; + + if (fstat(fd,&st) == 0) + if (st.st_size <= 0xffffffff) { + x = mmap(0,st.st_size,PROT_READ,MAP_SHARED,fd,0); + if (x + 1) { + c->size = st.st_size; + c->map = x; + } + } +} + +int cdb_read(struct cdb *c,char *buf,unsigned int len,uint32 pos) +{ + if (c->map) { + if ((pos > c->size) || (c->size - pos < len)) goto FORMAT; + byte_copy(buf,len,c->map + pos); + } + else { + if (seek_set(c->fd,pos) == -1) return -1; + while (len > 0) { + int r; + do + r = read(c->fd,buf,len); + while ((r == -1) && (errno == error_intr)); + if (r == -1) return -1; + if (r == 0) goto FORMAT; + buf += r; + len -= r; + } + } + return 0; + + FORMAT: + errno = error_proto; + return -1; +} + +static int match(struct cdb *c,const char *key,unsigned int len,uint32 pos) +{ + char buf[32]; + int n; + + while (len > 0) { + n = sizeof buf; + if (n > len) n = len; + if (cdb_read(c,buf,n,pos) == -1) return -1; + if (byte_diff(buf,n,key)) return 0; + pos += n; + key += n; + len -= n; + } + return 1; +} + +int cdb_findnext(struct cdb *c,const char *key,unsigned int len) +{ + char buf[8]; + uint32 pos; + uint32 u; + + if (!c->loop) { + u = cdb_hash(key,len); + if (cdb_read(c,buf,8,(u << 3) & 2047) == -1) return -1; + uint32_unpack(buf + 4,&c->hslots); + if (!c->hslots) return 0; + uint32_unpack(buf,&c->hpos); + c->khash = u; + u >>= 8; + u %= c->hslots; + u <<= 3; + c->kpos = c->hpos + u; + } + + while (c->loop < c->hslots) { + if (cdb_read(c,buf,8,c->kpos) == -1) return -1; + uint32_unpack(buf + 4,&pos); + if (!pos) return 0; + c->loop += 1; + c->kpos += 8; + if (c->kpos == c->hpos + (c->hslots << 3)) c->kpos = c->hpos; + uint32_unpack(buf,&u); + if (u == c->khash) { + if (cdb_read(c,buf,8,pos) == -1) return -1; + uint32_unpack(buf,&u); + if (u == len) + switch(match(c,key,len,pos + 8)) { + case -1: + return -1; + case 1: + uint32_unpack(buf + 4,&c->dlen); + c->dpos = pos + 8 + len; + return 1; + } + } + } + + return 0; +} + +int cdb_find(struct cdb *c,const char *key,unsigned int len) +{ + cdb_findstart(c); + return cdb_findnext(c,key,len); +} |