X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Fio.c;h=8f14d5b12e37563d101084e222c08d15b3fc0a4f;hp=9572e7412eccc4d6f3666c6ab11d786f7c08e91e;hb=d1cea3ebf96f61b5bbac1e74975700770e06add6;hpb=ebdd6451e2d7aa185e62a59fa2c72ffe36772d9a

diff --git a/ccan/tdb2/io.c b/ccan/tdb2/io.c
index 9572e741..8f14d5b1 100644
--- a/ccan/tdb2/io.c
+++ b/ccan/tdb2/io.c
@@ -26,6 +26,7 @@
    License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */
 #include "private.h"
+#include <assert.h>
 #include <ccan/likely/likely.h>
 
 void tdb_munmap(struct tdb_context *tdb)
@@ -47,8 +48,7 @@ void tdb_mmap(struct tdb_context *tdb)
 	if (tdb->flags & TDB_NOMMAP)
 		return;
 
-	tdb->map_ptr = mmap(NULL, tdb->map_size, 
-			    PROT_READ|(tdb->read_only? 0:PROT_WRITE), 
+	tdb->map_ptr = mmap(NULL, tdb->map_size, tdb->mmap_flags,
 			    MAP_SHARED, tdb->fd, 0);
 
 	/*
@@ -70,6 +70,13 @@ void tdb_mmap(struct tdb_context *tdb)
 static int tdb_oob(struct tdb_context *tdb, tdb_off_t len, bool probe)
 {
 	struct stat st;
+	int ret;
+
+	/* We can't hold pointers during this: we could unmap! */
+	assert(!tdb->direct_access
+	       || (tdb->flags & TDB_NOLOCK)
+	       || tdb_has_expansion_lock(tdb));
+
 	if (len <= tdb->map_size)
 		return 0;
 	if (tdb->flags & TDB_INTERNAL) {
@@ -85,7 +92,14 @@ static int tdb_oob(struct tdb_context *tdb, tdb_off_t len, bool probe)
 		return -1;
 	}
 
-	if (fstat(tdb->fd, &st) == -1) {
+	if (tdb_lock_expand(tdb, F_RDLCK) != 0)
+		return -1;
+
+	ret = fstat(tdb->fd, &st);
+
+	tdb_unlock_expand(tdb, F_RDLCK);
+
+	if (ret == -1) {
 		tdb->ecode = TDB_ERR_IO;
 		return -1;
 	}
@@ -103,6 +117,7 @@ static int tdb_oob(struct tdb_context *tdb, tdb_off_t len, bool probe)
 
 	/* Unmap, update size, remap */
 	tdb_munmap(tdb);
+
 	tdb->map_size = st.st_size;
 	tdb_mmap(tdb);
 	return 0;
@@ -132,19 +147,13 @@ void *tdb_get(struct tdb_context *tdb, tdb_off_t off, void *pad, size_t len)
 		if (ret)
 			return ret;
 	}
-
-	if (unlikely(tdb_oob(tdb, off + len, false) == -1))
-		return NULL;
-
-	if (tdb->methods->read(tdb, off, pad, len) == -1)
-		return NULL;
-	return tdb_convert(tdb, pad, len);
+	return tdb_read_convert(tdb, off, pad, len) == -1 ? NULL : pad;
 }
 
 /* Endian conversion: we only ever deal with 8 byte quantities */
 void *tdb_convert(const struct tdb_context *tdb, void *buf, tdb_len_t size)
 {
-	if (unlikely((tdb->flags & TDB_CONVERT))) {
+	if (unlikely((tdb->flags & TDB_CONVERT)) && buf) {
 		uint64_t i, *p = (uint64_t *)buf;
 		for (i = 0; i < size / 8; i++)
 			p[i] = bswap_64(p[i]);
@@ -152,84 +161,63 @@ void *tdb_convert(const struct tdb_context *tdb, void *buf, tdb_len_t size)
 	return buf;
 }
 
-/* Return first non-zero offset in num offset array, or num. */
 /* FIXME: Return the off? */
-uint64_t tdb_find_nonzero_off(struct tdb_context *tdb, tdb_off_t off,
-			      uint64_t num)
-{
-	uint64_t i, *val;
-	bool alloc = false;
-
-	val = tdb_direct(tdb, off, num * sizeof(tdb_off_t));
-	if (!unlikely(val)) {
-		val = tdb_alloc_read(tdb, off, num * sizeof(tdb_off_t));
-		if (!val)
-			return num;
-		alloc = true;
-	}
+uint64_t tdb_find_nonzero_off(struct tdb_context *tdb,
+			      tdb_off_t base, uint64_t start, uint64_t end)
+{
+	uint64_t i;
+	const uint64_t *val;
 
-	for (i = 0; i < num; i++) {
+	/* Zero vs non-zero is the same unconverted: minor optimization. */
+	val = tdb_access_read(tdb, base + start * sizeof(tdb_off_t),
+			      (end - start) * sizeof(tdb_off_t), false);
+	if (!val)
+		return end;
+
+	for (i = 0; i < (end - start); i++) {
 		if (val[i])
 			break;
 	}
-	if (unlikely(alloc))
-		free(val);
-	return i;
+	tdb_access_release(tdb, val);
+	return start + i;
 }
 
 /* Return first zero offset in num offset array, or num. */
 uint64_t tdb_find_zero_off(struct tdb_context *tdb, tdb_off_t off,
 			   uint64_t num)
 {
-	uint64_t i, *val;
-	bool alloc = false;
+	uint64_t i;
+	const uint64_t *val;
 
-	val = tdb_direct(tdb, off, num * sizeof(tdb_off_t));
-	if (!unlikely(val)) {
-		val = tdb_alloc_read(tdb, off, num * sizeof(tdb_off_t));
-		if (!val)
-			return num;
-		alloc = true;
-	}
+	/* Zero vs non-zero is the same unconverted: minor optimization. */
+	val = tdb_access_read(tdb, off, num * sizeof(tdb_off_t), false);
+	if (!val)
+		return num;
 
 	for (i = 0; i < num; i++) {
 		if (!val[i])
 			break;
 	}
-	if (unlikely(alloc))
-		free(val);
+	tdb_access_release(tdb, val);
 	return i;
 }
 
-static int fill(struct tdb_context *tdb,
-		const void *buf, size_t size,
-		tdb_off_t off, tdb_len_t len)
-{
-	while (len) {
-		size_t n = len > size ? size : len;
-
-		if (!tdb_pwrite_all(tdb->fd, buf, n, off)) {
-			tdb->ecode = TDB_ERR_IO;
-			tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
-				 "fill write failed: giving up!\n");
-			return -1;
-		}
-		len -= n;
-		off += n;
-	}
-	return 0;
-}
-
 int zero_out(struct tdb_context *tdb, tdb_off_t off, tdb_len_t len)
 {
+	char buf[8192] = { 0 };
 	void *p = tdb_direct(tdb, off, len);
 	if (p) {
 		memset(p, 0, len);
 		return 0;
-	} else {
-		char buf[8192] = { 0 };
-		return fill(tdb, buf, sizeof(buf), len, off);
 	}
+	while (len) {
+		unsigned todo = len < sizeof(buf) ? len : sizeof(buf);
+		if (tdb->methods->write(tdb, off, buf, todo) == -1)
+			return -1;
+		len -= todo;
+		off += todo;
+	}
+	return 0;
 }
 
 tdb_off_t tdb_read_off(struct tdb_context *tdb, tdb_off_t off)
@@ -323,7 +311,8 @@ static int tdb_write(struct tdb_context *tdb, tdb_off_t off,
 			tdb->ecode = TDB_ERR_IO;
 			tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
 				 "tdb_write failed at %llu len=%llu (%s)\n",
-				 off, len, strerror(errno));
+				 (long long)off, (long long)len,
+				 strerror(errno));
 			return -1;
 		}
 	}
@@ -357,9 +346,26 @@ static int tdb_read(struct tdb_context *tdb, tdb_off_t off, void *buf,
 }
 
 int tdb_write_convert(struct tdb_context *tdb, tdb_off_t off,
-		      void *rec, size_t len)
+		      const void *rec, size_t len)
 {
-	return tdb->methods->write(tdb, off, tdb_convert(tdb, rec, len), len);
+	int ret;
+	if (unlikely((tdb->flags & TDB_CONVERT))) {
+		void *conv = malloc(len);
+		if (!conv) {
+			tdb->ecode = TDB_ERR_OOM;
+			tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
+				 "tdb_write: no memory converting %zu bytes\n",
+				 len);
+			return -1;
+		}
+		memcpy(conv, rec, len);
+		ret = tdb->methods->write(tdb, off,
+					  tdb_convert(tdb, conv, len), len);
+		free(conv);
+	} else
+		ret = tdb->methods->write(tdb, off, rec, len);
+
+	return ret;
 }
 
 int tdb_read_convert(struct tdb_context *tdb, tdb_off_t off,
@@ -375,78 +381,53 @@ int tdb_write_off(struct tdb_context *tdb, tdb_off_t off, tdb_off_t val)
 	return tdb_write_convert(tdb, off, &val, sizeof(val));
 }
 
-/* read a lump of data, allocating the space for it */
-void *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len)
+static void *_tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset,
+			     tdb_len_t len, unsigned int prefix)
 {
 	void *buf;
 
 	/* some systems don't like zero length malloc */
-	buf = malloc(len ? len : 1);
+	buf = malloc(prefix + len ? prefix + len : 1);
 	if (unlikely(!buf)) {
 		tdb->ecode = TDB_ERR_OOM;
 		tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
 			 "tdb_alloc_read malloc failed len=%lld\n",
-			 (long long)len);
-	} else if (unlikely(tdb->methods->read(tdb, offset, buf, len))) {
+			 (long long)prefix + len);
+	} else if (unlikely(tdb->methods->read(tdb, offset, buf+prefix, len))) {
 		free(buf);
 		buf = NULL;
 	}
 	return buf;
 }
 
-uint64_t hash_record(struct tdb_context *tdb, tdb_off_t off)
+/* read a lump of data, allocating the space for it */
+void *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len)
 {
-	struct tdb_used_record pad, *r;
-	void *key;
-	uint64_t klen, hash;
-
-	r = tdb_get(tdb, off, &pad, sizeof(pad));
-	if (!r)
-		/* FIXME */
-		return 0;
+	return _tdb_alloc_read(tdb, offset, len, 0);
+}
 
-	klen = rec_key_length(r);
-	key = tdb_direct(tdb, off + sizeof(pad), klen);
-	if (likely(key))
-		return tdb_hash(tdb, key, klen);
+static int fill(struct tdb_context *tdb,
+		const void *buf, size_t size,
+		tdb_off_t off, tdb_len_t len)
+{
+	while (len) {
+		size_t n = len > size ? size : len;
 
-	key = tdb_alloc_read(tdb, off + sizeof(pad), klen);
-	if (unlikely(!key))
-		return 0;
-	hash = tdb_hash(tdb, key, klen);
-	free(key);
-	return hash;
-}
-
-/* Give a piece of tdb data to a parser */
-int tdb_parse_data(struct tdb_context *tdb, TDB_DATA key,
-		   tdb_off_t offset, tdb_len_t len,
-		   int (*parser)(TDB_DATA key, TDB_DATA data,
-				 void *private_data),
-		   void *private_data)
-{
-	TDB_DATA data;
-	int result;
-	bool allocated = false;
-
-	data.dsize = len;
-	data.dptr = tdb_direct(tdb, offset, len);
-	if (unlikely(!data.dptr)) {
-		if (!(data.dptr = tdb_alloc_read(tdb, offset, len))) {
+		if (!tdb_pwrite_all(tdb->fd, buf, n, off)) {
+			tdb->ecode = TDB_ERR_IO;
+			tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
+				 "fill write failed: giving up!\n");
 			return -1;
 		}
-		allocated = true;
+		len -= n;
+		off += n;
 	}
-	result = parser(key, data, private_data);
-	if (unlikely(allocated))
-		free(data.dptr);
-	return result;
+	return 0;
 }
 
 /* expand a file.  we prefer to use ftruncate, as that is what posix
   says to use for mmap expansion */
-static int tdb_expand_file(struct tdb_context *tdb,
-			   tdb_len_t size, tdb_len_t addition)
+static int tdb_expand_file(struct tdb_context *tdb, tdb_len_t addition)
 {
 	char buf[8192];
 
@@ -455,24 +436,86 @@ static int tdb_expand_file(struct tdb_context *tdb,
 		return -1;
 	}
 
-	/* If this fails, we try to fill anyway. */
-	if (ftruncate(tdb->fd, size+addition))
-		;
+	if (tdb->flags & TDB_INTERNAL) {
+		char *new = realloc(tdb->map_ptr, tdb->map_size + addition);
+		if (!new) {
+			tdb->ecode = TDB_ERR_OOM;
+			return -1;
+		}
+		tdb->map_ptr = new;
+		tdb->map_size += addition;
+	} else {
+		/* Unmap before trying to write; old TDB claimed OpenBSD had
+		 * problem with this otherwise. */
+		tdb_munmap(tdb);
 
-	/* now fill the file with something. This ensures that the
-	   file isn't sparse, which would be very bad if we ran out of
-	   disk. This must be done with write, not via mmap */
-	memset(buf, 0x43, sizeof(buf));
-	return fill(tdb, buf, sizeof(buf), addition, size);
+		/* If this fails, we try to fill anyway. */
+		if (ftruncate(tdb->fd, tdb->map_size + addition))
+			;
+
+		/* now fill the file with something. This ensures that the
+		   file isn't sparse, which would be very bad if we ran out of
+		   disk. This must be done with write, not via mmap */
+		memset(buf, 0x43, sizeof(buf));
+		if (fill(tdb, buf, sizeof(buf), tdb->map_size, addition) == -1)
+			return -1;
+		tdb->map_size += addition;
+		tdb_mmap(tdb);
+	}
+	return 0;
 }
 
+/* This is only neded for tdb_access_commit, but used everywhere to simplify. */
+struct tdb_access_hdr {
+	tdb_off_t off;
+	tdb_len_t len;
+	bool convert;
+};
+
 const void *tdb_access_read(struct tdb_context *tdb,
-			    tdb_off_t off, tdb_len_t len)
+			    tdb_off_t off, tdb_len_t len, bool convert)
 {
-	const void *ret = tdb_direct(tdb, off, len);
+	const void *ret = NULL;	
+
+	if (likely(!(tdb->flags & TDB_CONVERT)))
+		ret = tdb_direct(tdb, off, len);
+
+	if (!ret) {
+		struct tdb_access_hdr *hdr;
+		hdr = _tdb_alloc_read(tdb, off, len, sizeof(*hdr));
+		if (hdr) {
+			ret = hdr + 1;
+			if (convert)
+				tdb_convert(tdb, (void *)ret, len);
+		}
+	} else
+		tdb->direct_access++;
+
+	return ret;
+}
+
+void *tdb_access_write(struct tdb_context *tdb,
+		       tdb_off_t off, tdb_len_t len, bool convert)
+{
+	void *ret = NULL;
+
+	if (likely(!(tdb->flags & TDB_CONVERT)))
+		ret = tdb_direct(tdb, off, len);
+
+	if (!ret) {
+		struct tdb_access_hdr *hdr;
+		hdr = _tdb_alloc_read(tdb, off, len, sizeof(*hdr));
+		if (hdr) {
+			hdr->off = off;
+			hdr->len = len;
+			hdr->convert = convert;
+			ret = hdr + 1;
+			if (convert)
+				tdb_convert(tdb, (void *)ret, len);
+		}
+	} else
+		tdb->direct_access++;
 
-	if (!ret)
-		ret = tdb_alloc_read(tdb, off, len);
 	return ret;
 }
 
@@ -481,7 +524,30 @@ void tdb_access_release(struct tdb_context *tdb, const void *p)
 	if (!tdb->map_ptr
 	    || (char *)p < (char *)tdb->map_ptr
 	    || (char *)p >= (char *)tdb->map_ptr + tdb->map_size)
-		free((void *)p);
+		free((struct tdb_access_hdr *)p - 1);
+	else
+		tdb->direct_access--;
+}
+
+int tdb_access_commit(struct tdb_context *tdb, void *p)
+{
+	int ret = 0;
+
+	if (!tdb->map_ptr
+	    || (char *)p < (char *)tdb->map_ptr
+	    || (char *)p >= (char *)tdb->map_ptr + tdb->map_size) {
+		struct tdb_access_hdr *hdr;
+
+		hdr = (struct tdb_access_hdr *)p - 1;
+		if (hdr->convert)
+			ret = tdb_write_convert(tdb, hdr->off, p, hdr->len);
+		else
+			ret = tdb_write(tdb, hdr->off, p, hdr->len);
+		free(hdr);
+	} else
+		tdb->direct_access--;
+
+	return ret;
 }
 
 #if 0
@@ -558,84 +624,6 @@ static void tdb_next_hash_chain(struct tdb_context *tdb, uint32_t *chain)
 	(*chain) = h;
 }
 
-
-/* expand the database by expanding the underlying file and doing the
-   mmap again if necessary */
-int tdb_expand(struct tdb_context *tdb)
-{
-	struct tdb_record rec;
-	tdb_off_t offset, new_size;	
-
-	/* We have to lock every hash bucket and every free list. */
-	do {
-		
-
-	if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "lock failed in tdb_expand\n"));
-		return -1;
-	}
-
-	/* must know about any previous expansions by another process */
-	tdb->methods->tdb_oob(tdb, tdb->map_size + 1, 1);
-
-	/* always make room for at least 100 more records, and at
-           least 25% more space. Round the database up to a multiple
-           of the page size */
-	new_size = MAX(tdb->map_size + size*100, tdb->map_size * 1.25);
-	size = TDB_ALIGN(new_size, tdb->page_size) - tdb->map_size;
-
-	if (!(tdb->flags & TDB_INTERNAL))
-		tdb_munmap(tdb);
-
-	/*
-	 * We must ensure the file is unmapped before doing this
-	 * to ensure consistency with systems like OpenBSD where
-	 * writes and mmaps are not consistent.
-	 */
-
-	/* expand the file itself */
-	if (!(tdb->flags & TDB_INTERNAL)) {
-		if (tdb->methods->tdb_expand_file(tdb, tdb->map_size, size) != 0)
-			goto fail;
-	}
-
-	tdb->map_size += size;
-
-	if (tdb->flags & TDB_INTERNAL) {
-		char *new_map_ptr = (char *)realloc(tdb->map_ptr,
-						    tdb->map_size);
-		if (!new_map_ptr) {
-			tdb->map_size -= size;
-			goto fail;
-		}
-		tdb->map_ptr = new_map_ptr;
-	} else {
-		/*
-		 * We must ensure the file is remapped before adding the space
-		 * to ensure consistency with systems like OpenBSD where
-		 * writes and mmaps are not consistent.
-		 */
-
-		/* We're ok if the mmap fails as we'll fallback to read/write */
-		tdb_mmap(tdb);
-	}
-
-	/* form a new freelist record */
-	memset(&rec,'\0',sizeof(rec));
-	rec.rec_len = size - sizeof(rec);
-
-	/* link it into the free list */
-	offset = tdb->map_size - size;
-	if (tdb_free(tdb, offset, &rec) == -1)
-		goto fail;
-
-	tdb_unlock(tdb, -1, F_WRLCK);
-	return 0;
- fail:
-	tdb_unlock(tdb, -1, F_WRLCK);
-	return -1;
-}
-
 /* read/write a tdb_off_t */
 int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d)
 {