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authorLaurent Bercot <ska-skaware@skarnet.org>2014-09-18 18:55:44 +0000
committerLaurent Bercot <ska-skaware@skarnet.org>2014-09-18 18:55:44 +0000
commit3534b428629be185e096be99e3bd5fdfe32d5544 (patch)
tree210ef3198ed66bc7f7b7bf6a85e4579f455e5a36 /src/libstddjb/cdb_findnext.c
downloadskalibs-3534b428629be185e096be99e3bd5fdfe32d5544.tar.xz
initial commit with rc for skalibs-2.0.0.0
Diffstat (limited to 'src/libstddjb/cdb_findnext.c')
-rw-r--r--src/libstddjb/cdb_findnext.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/src/libstddjb/cdb_findnext.c b/src/libstddjb/cdb_findnext.c
new file mode 100644
index 0000000..2559bc2
--- /dev/null
+++ b/src/libstddjb/cdb_findnext.c
@@ -0,0 +1,67 @@
+/* ISC license. */
+
+#include <skalibs/bytestr.h>
+#include <skalibs/uint32.h>
+#include <skalibs/cdb.h>
+
+static int match (struct cdb *c, char const *key, unsigned int len, uint32 pos)
+{
+ char buf[1024] ;
+ while (len > 0)
+ {
+ register unsigned int n = 1024 ;
+ if (n > len) n = len ;
+ if (cdb_read(c, buf, n, pos) < 0) return -1 ;
+ if (byte_diff(buf, n, key)) return 0 ;
+ pos += n ; key += n ; len -= n ;
+ }
+ return 1 ;
+}
+
+int cdb_findnext (struct cdb *c, char const *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) < 0) 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) < 0) return -1 ;
+ uint32_unpack(buf + 4, &pos) ;
+ if (!pos) return 0 ;
+ c->loop++ ;
+ 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) < 0) 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 ;
+}