tdb2: remove looping for read on normal files.

[ccan] / ccan / tdb2 / io.c

diff --git a/ccan/tdb2/io.c b/ccan/tdb2/io.c
index ffd952d2aae3d23acab3af69b3ebc08ce9850ada..999922b12e517c63be16ce1b20d7d22d077f9acc 100644 (file)
--- a/ccan/tdb2/io.c
+++ b/ccan/tdb2/io.c
@@ -225,44 +225,6 @@ bool tdb_pwrite_all(int fd, const void *buf, size_t len, tdb_off_t off)
        return true;
 }
 
-/* Even on files, we can get partial reads due to signals. */
-bool tdb_pread_all(int fd, void *buf, size_t len, tdb_off_t off)
-{
-       while (len) {
-               ssize_t ret;
-               ret = pread(fd, buf, len, off);
-               if (ret < 0)
-                       return false;
-               if (ret == 0) {
-                       /* ETOOSHORT? */
-                       errno = EWOULDBLOCK;
-                       return false;
-               }
-               buf = (char *)buf + ret;
-               off += ret;
-               len -= ret;
-       }
-       return true;
-}
-
-bool tdb_read_all(int fd, void *buf, size_t len)
-{
-       while (len) {
-               ssize_t ret;
-               ret = read(fd, buf, len);
-               if (ret < 0)
-                       return false;
-               if (ret == 0) {
-                       /* ETOOSHORT? */
-                       errno = EWOULDBLOCK;
-                       return false;
-               }
-               buf = (char *)buf + ret;
-               len -= ret;
-       }
-       return true;
-}
-
 /* write a lump of data at a specified offset */
 static int tdb_write(struct tdb_context *tdb, tdb_off_t off, 
                     const void *buf, tdb_len_t len)
@@ -305,13 +267,14 @@ static int tdb_read(struct tdb_context *tdb, tdb_off_t off, void *buf,
        if (tdb->map_ptr) {
                memcpy(buf, off + (char *)tdb->map_ptr, len);
        } else {
-               if (!tdb_pread_all(tdb->fd, buf, len, off)) {
+               ssize_t r = pread(tdb->fd, buf, len, off);
+               if (r != len) {
                        tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_FATAL,
-                                  "tdb_read failed at %zu "
+                                  "tdb_read failed with %zi at %zu "
                                   "len=%zu (%s) map_size=%zu",
-                                (size_t)off, (size_t)len,
-                                strerror(errno),
-                                (size_t)tdb->map_size);
+                                  r, (size_t)off, (size_t)len,
+                                  strerror(errno),
+                                  (size_t)tdb->map_size);
                        return -1;
                }
        }
@@ -452,13 +415,6 @@ static int tdb_expand_file(struct tdb_context *tdb, tdb_len_t addition)
        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, bool convert)
 {
@@ -471,6 +427,8 @@ const void *tdb_access_read(struct tdb_context *tdb,
                struct tdb_access_hdr *hdr;
                hdr = _tdb_alloc_read(tdb, off, len, sizeof(*hdr));
                if (hdr) {
+                       hdr->next = tdb->access;
+                       tdb->access = hdr;
                        ret = hdr + 1;
                        if (convert)
                                tdb_convert(tdb, (void *)ret, len);
@@ -499,6 +457,8 @@ void *tdb_access_write(struct tdb_context *tdb,
                struct tdb_access_hdr *hdr;
                hdr = _tdb_alloc_read(tdb, off, len, sizeof(*hdr));
                if (hdr) {
+                       hdr->next = tdb->access;
+                       tdb->access = hdr;
                        hdr->off = off;
                        hdr->len = len;
                        hdr->convert = convert;
@@ -512,35 +472,41 @@ void *tdb_access_write(struct tdb_context *tdb,
        return ret;
 }
 
-bool is_direct(const struct tdb_context *tdb, const void *p)
+static struct tdb_access_hdr **find_hdr(struct tdb_context *tdb, const void *p)
 {
-       return (tdb->map_ptr
-               && (char *)p >= (char *)tdb->map_ptr
-               && (char *)p < (char *)tdb->map_ptr + tdb->map_size);
+       struct tdb_access_hdr **hp;
+
+       for (hp = &tdb->access; *hp; hp = &(*hp)->next) {
+               if (*hp + 1 == p)
+                       return hp;
+       }
+       return NULL;
 }
 
 void tdb_access_release(struct tdb_context *tdb, const void *p)
 {
-       if (is_direct(tdb, p))
+       struct tdb_access_hdr *hdr, **hp = find_hdr(tdb, p);
+
+       if (hp) {
+               hdr = *hp;
+               *hp = hdr->next;
+               free(hdr);
+       } else
                tdb->direct_access--;
-       else
-               free((struct tdb_access_hdr *)p - 1);
 }
 
 int tdb_access_commit(struct tdb_context *tdb, void *p)
 {
+       struct tdb_access_hdr *hdr, **hp = find_hdr(tdb, 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 (hp) {
+               hdr = *hp;
                if (hdr->convert)
                        ret = tdb_write_convert(tdb, hdr->off, p, hdr->len);
                else
                        ret = tdb_write(tdb, hdr->off, p, hdr->len);
+               *hp = hdr->next;
                free(hdr);
        } else
                tdb->direct_access--;
@@ -549,7 +515,7 @@ int tdb_access_commit(struct tdb_context *tdb, void *p)
 }
 
 static void *tdb_direct(struct tdb_context *tdb, tdb_off_t off, size_t len,
-                       bool write)
+                       bool write_mode)
 {
        if (unlikely(!tdb->map_ptr))
                return NULL;
@@ -559,10 +525,10 @@ static void *tdb_direct(struct tdb_context *tdb, tdb_off_t off, size_t len,
        return (char *)tdb->map_ptr + off;
 }
 
-void add_stat_(struct tdb_context *tdb, uint64_t *stat, size_t val)
+void add_stat_(struct tdb_context *tdb, uint64_t *s, size_t val)
 {
-       if ((uintptr_t)stat < (uintptr_t)tdb->stats + tdb->stats->size)
-               *stat += val;
+       if ((uintptr_t)s < (uintptr_t)tdb->stats + tdb->stats->size)
+               *s += val;
 }
 
 static const struct tdb_methods io_methods = {