Remove the dependency on SQLite without loss of functionality.

Stop supporting systems that don't have mmap(3).
Drop the obsolete names_check() now that we deleted MLINKS.

1 files changed, 174 insertions, 0 deletions

diff --git a/dbm_map.c b/dbm_map.c
new file mode 100644
index 00000000..8d24832d
--- /dev/null
+++ b/dbm_map.c
@@ -0,0 +1,174 @@
+/*	$Id$ */
+/*
+ * Copyright (c) 2016 Ingo Schwarze <schwarze@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Low-level routines for the map-based version
+ * of the mandoc database, for read-only access.
+ * The interface is defined in "dbm_map.h".
+ */
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <endian.h>
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <regex.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "mansearch.h"
+#include "dbm_map.h"
+#include "dbm.h"
+
+static struct stat	 st;
+static char		*dbm_base;
+static int		 ifd;
+static int32_t		 max_offset;
+
+/*
+ * Open a disk-based database for read-only access.
+ * Validate the file format as far as it is not mandoc-specific.
+ * Return 0 on success.  Return -1 and set errno on failure.
+ */
+int
+dbm_map(const char *fname)
+{
+	int		 save_errno;
+	const int32_t	*magic;
+
+	if ((ifd = open(fname, O_RDONLY)) == -1)
+		return -1;
+	if (fstat(ifd, &st) == -1)
+		goto fail;
+	if (st.st_size < 5) {
+		warnx("dbm_map(%s): File too short", fname);
+		errno = EFTYPE;
+		goto fail;
+	}
+	if (st.st_size > INT32_MAX) {
+		errno = EFBIG;
+		goto fail;
+	}
+	if ((dbm_base = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED,
+	    ifd, 0)) == MAP_FAILED)
+		goto fail;
+	magic = dbm_getint(0);
+	if (be32toh(*magic) != MANDOCDB_MAGIC) {
+		warnx("dbm_map(%s): Bad initial magic %x (expected %x)",
+		    fname, be32toh(*magic), MANDOCDB_MAGIC);
+		errno = EFTYPE;
+		goto fail;
+	}
+	magic = dbm_getint(1);
+	if (be32toh(*magic) != MANDOCDB_VERSION) {
+		warnx("dbm_map(%s): Bad version number %d (expected %d)",
+		    fname, be32toh(*magic), MANDOCDB_VERSION);
+		errno = EFTYPE;
+		goto fail;
+	}
+	max_offset = be32toh(*dbm_getint(3)) + sizeof(int32_t);
+	if (st.st_size != max_offset) {
+		warnx("dbm_map(%s): Inconsistent file size %llu (expected %d)",
+		    fname, st.st_size, max_offset);
+		errno = EFTYPE;
+		goto fail;
+	}
+	if ((magic = dbm_get(*dbm_getint(3))) == NULL) {
+		errno = EFTYPE;
+		goto fail;
+	}
+	if (be32toh(*magic) != MANDOCDB_MAGIC) {
+		warnx("dbm_map(%s): Bad final magic %x (expected %x)",
+		    fname, be32toh(*magic), MANDOCDB_MAGIC);
+		errno = EFTYPE;
+		goto fail;
+	}
+	return 0;
+
+fail:
+	save_errno = errno;
+	close(ifd);
+	errno = save_errno;
+	return -1;
+}
+
+void
+dbm_unmap(void)
+{
+	if (munmap(dbm_base, st.st_size) == -1)
+		warn("dbm_unmap: munmap");
+	if (close(ifd) == -1)
+		warn("dbm_unmap: close");
+	dbm_base = (char *)-1;
+}
+
+/*
+ * Take a raw integer as it was read from the database.
+ * Interpret it as an offset into the database file
+ * and return a pointer to that place in the file.
+ */
+void *
+dbm_get(int32_t offset)
+{
+	offset = be32toh(offset);
+	if (offset < 0 || offset >= max_offset) {
+		warnx("dbm_get: Database corrupt: offset %d > %d",
+		    offset, max_offset);
+		return NULL;
+	}
+	return dbm_base + offset;
+}
+
+/*
+ * Assume the database starts with some integers.
+ * Assume they are numbered starting from 0, increasing.
+ * Get a pointer to one with the number "offset".
+ */
+int32_t *
+dbm_getint(int32_t offset)
+{
+	return (int32_t *)dbm_base + offset;
+}
+
+/*
+ * The reverse of dbm_get().
+ * Take pointer into the database file
+ * and convert it to the raw integer
+ * that would be used to refer to that place in the file.
+ */
+int32_t
+dbm_addr(const void *p)
+{
+	return htobe32((char *)p - dbm_base);
+}
+
+int
+dbm_match(const struct dbm_match *match, const char *str)
+{
+	switch (match->type) {
+	case DBM_EXACT:
+		return strcmp(str, match->str) == 0;
+	case DBM_SUB:
+		return strcasestr(str, match->str) != NULL;
+	case DBM_REGEX:
+		return regexec(match->re, str, 0, NULL, 0) == 0;
+	default:
+		abort();
+	}
+}