by various parts of the Samba code
Copyright (C) Rafal Szczesniak 2002
+ Copyright (C) Volker Lendecke 2009
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
*/
#include "includes.h"
+#include "system/filesys.h"
+#include "system/glob.h"
+#include "util_tdb.h"
+#include "tdb_wrap/tdb_wrap.h"
+#include "../lib/util/memcache.h"
#undef DBGC_CLASS
#define DBGC_CLASS DBGC_TDB
#define TIMEOUT_LEN 12
-#define CACHE_DATA_FMT "%12u/%s"
+#define CACHE_DATA_FMT "%12u/"
#define READ_CACHE_DATA_FMT_TEMPLATE "%%12u/%%%us"
#define BLOB_TYPE "DATA_BLOB"
#define BLOB_TYPE_LEN 9
-static TDB_CONTEXT *cache;
+static struct tdb_wrap *cache;
+static struct tdb_wrap *cache_notrans;
+static int cache_notrans_seqnum;
/**
* @file gencache.c
* false on failure
**/
-bool gencache_init(void)
+static bool gencache_init(void)
{
char* cache_fname = NULL;
+ int open_flags = O_RDWR|O_CREAT;
/* skip file open if it's already opened */
if (cache) return True;
- cache_fname = lock_path("gencache.tdb");
+ cache_fname = cache_path("gencache.tdb");
+ if (cache_fname == NULL) {
+ return false;
+ }
DEBUG(5, ("Opening cache file at %s\n", cache_fname));
- cache = tdb_open_log(cache_fname, 0, TDB_DEFAULT,
- O_RDWR|O_CREAT, 0644);
+ cache = tdb_wrap_open(NULL, cache_fname, 0,
+ TDB_DEFAULT|TDB_INCOMPATIBLE_HASH,
+ open_flags, 0644);
+ if (cache) {
+ int ret;
+ ret = tdb_check(cache->tdb, NULL, NULL);
+ if (ret != 0) {
+ TALLOC_FREE(cache);
+
+ /*
+ * Retry with CLEAR_IF_FIRST.
+ *
+ * Warning: Converting this to dbwrap won't work
+ * directly. gencache.c does transactions on this tdb,
+ * and dbwrap forbids this for CLEAR_IF_FIRST
+ * databases. tdb does allow transactions on
+ * CLEAR_IF_FIRST databases, so lets use it here to
+ * clean up a broken database.
+ */
+ cache = tdb_wrap_open(NULL, cache_fname, 0,
+ TDB_DEFAULT|
+ TDB_INCOMPATIBLE_HASH|
+ TDB_CLEAR_IF_FIRST,
+ open_flags, 0644);
+ }
+ }
if (!cache && (errno == EACCES)) {
- cache = tdb_open_log(cache_fname, 0, TDB_DEFAULT, O_RDONLY, 0644);
+ open_flags = O_RDONLY;
+ cache = tdb_wrap_open(NULL, cache_fname, 0,
+ TDB_DEFAULT|TDB_INCOMPATIBLE_HASH,
+ open_flags, 0644);
if (cache) {
DEBUG(5, ("gencache_init: Opening cache file %s read-only.\n", cache_fname));
}
}
+ TALLOC_FREE(cache_fname);
if (!cache) {
DEBUG(5, ("Attempt to open gencache.tdb has failed.\n"));
return False;
}
+
+ cache_fname = lock_path("gencache_notrans.tdb");
+ if (cache_fname == NULL) {
+ TALLOC_FREE(cache);
+ return false;
+ }
+
+ DEBUG(5, ("Opening cache file at %s\n", cache_fname));
+
+ cache_notrans = tdb_wrap_open(NULL, cache_fname, 0,
+ TDB_CLEAR_IF_FIRST|
+ TDB_INCOMPATIBLE_HASH|
+ TDB_SEQNUM|
+ TDB_NOSYNC|
+ TDB_MUTEX_LOCKING,
+ open_flags, 0644);
+ if (cache_notrans == NULL) {
+ DEBUG(5, ("Opening %s failed: %s\n", cache_fname,
+ strerror(errno)));
+ TALLOC_FREE(cache_fname);
+ TALLOC_FREE(cache);
+ return false;
+ }
+ TALLOC_FREE(cache_fname);
+
return True;
}
+static TDB_DATA last_stabilize_key(void)
+{
+ TDB_DATA result;
+ result.dptr = discard_const_p(uint8_t, "@LAST_STABILIZED");
+ result.dsize = 17;
+ return result;
+}
-/**
- * Cache shutdown function. Closes opened cache tdb file.
- *
- * @return true on successful closing the cache or
- * false on failure during cache shutdown
- **/
+struct gencache_have_val_state {
+ time_t new_timeout;
+ const DATA_BLOB *data;
+ bool gotit;
+};
-bool gencache_shutdown(void)
+static void gencache_have_val_parser(time_t old_timeout, DATA_BLOB data,
+ void *private_data)
{
- int ret;
- /* tdb_close routine returns -1 on error */
- if (!cache) return False;
- DEBUG(5, ("Closing cache file\n"));
- ret = tdb_close(cache);
- cache = NULL;
- return ret != -1;
+ struct gencache_have_val_state *state =
+ (struct gencache_have_val_state *)private_data;
+ time_t now = time(NULL);
+ int cache_time_left, new_time_left, additional_time;
+
+ /*
+ * Excuse the many variables, but these time calculations are
+ * confusing to me. We do not want to write to gencache with a
+ * possibly expensive transaction if we are about to write the same
+ * value, just extending the remaining timeout by less than 10%.
+ */
+
+ cache_time_left = old_timeout - now;
+ if (cache_time_left <= 0) {
+ /*
+ * timed out, write new value
+ */
+ return;
+ }
+
+ new_time_left = state->new_timeout - now;
+ if (new_time_left <= 0) {
+ /*
+ * Huh -- no new timeout?? Write it.
+ */
+ return;
+ }
+
+ if (new_time_left < cache_time_left) {
+ /*
+ * Someone wants to shorten the timeout. Let it happen.
+ */
+ return;
+ }
+
+ /*
+ * By how much does the new timeout extend the remaining cache time?
+ */
+ additional_time = new_time_left - cache_time_left;
+
+ if (additional_time * 10 < 0) {
+ /*
+ * Integer overflow. We extend by so much that we have to write it.
+ */
+ return;
+ }
+
+ /*
+ * The comparison below is essentially equivalent to
+ *
+ * new_time_left > cache_time_left * 1.10
+ *
+ * but without floating point calculations.
+ */
+
+ if (additional_time * 10 > cache_time_left) {
+ /*
+ * We extend the cache timeout by more than 10%. Do it.
+ */
+ return;
+ }
+
+ /*
+ * Now the more expensive data compare.
+ */
+ if (data_blob_cmp(state->data, &data) != 0) {
+ /*
+ * Write a new value. Certainly do it.
+ */
+ return;
+ }
+
+ /*
+ * Extending the timeout by less than 10% for the same cache value is
+ * not worth the trouble writing a value into gencache under a
+ * possibly expensive transaction.
+ */
+ state->gotit = true;
}
+static bool gencache_have_val(const char *keystr, const DATA_BLOB *data,
+ time_t timeout)
+{
+ struct gencache_have_val_state state;
+
+ state.new_timeout = timeout;
+ state.data = data;
+ state.gotit = false;
+
+ if (!gencache_parse(keystr, gencache_have_val_parser, &state)) {
+ return false;
+ }
+ return state.gotit;
+}
+
+static int last_stabilize_parser(TDB_DATA key, TDB_DATA data,
+ void *private_data)
+{
+ time_t *last_stabilize = private_data;
+
+ if ((data.dsize != 0) && (data.dptr[data.dsize-1] == '\0')) {
+ *last_stabilize = atoi((char *)data.dptr);
+ }
+ return 0;
+}
/**
* Set an entry in the cache file. If there's no such
* one, then add it.
*
* @param keystr string that represents a key of this entry
- * @param value text representation value being cached
+ * @param blob DATA_BLOB value being cached
* @param timeout time when the value is expired
*
* @retval true when entry is successfuly stored
* @retval false on failure
**/
-bool gencache_set(const char *keystr, const char *value, time_t timeout)
+bool gencache_set_data_blob(const char *keystr, const DATA_BLOB *blob,
+ time_t timeout)
{
int ret;
- TDB_DATA databuf;
- char* valstr = NULL;
+ char* val;
+ time_t last_stabilize;
+ static int writecount;
- if ((keystr == NULL) || (value == NULL)) {
+ if (tdb_data_cmp(string_term_tdb_data(keystr),
+ last_stabilize_key()) == 0) {
+ DEBUG(10, ("Can't store %s as a key\n", keystr));
+ return false;
+ }
+
+ if ((keystr == NULL) || (blob == NULL)) {
return false;
}
if (!gencache_init()) return False;
- if (asprintf(&valstr, CACHE_DATA_FMT, (int)timeout, value) == -1) {
+ if (gencache_have_val(keystr, blob, timeout)) {
+ DEBUG(10, ("Did not store value for %s, we already got it\n",
+ keystr));
+ return true;
+ }
+
+ val = talloc_asprintf(talloc_tos(), CACHE_DATA_FMT, (int)timeout);
+ if (val == NULL) {
return False;
}
+ val = talloc_realloc(NULL, val, char, talloc_array_length(val)-1);
+ if (val == NULL) {
+ return false;
+ }
+ val = (char *)talloc_append_blob(NULL, val, *blob);
+ if (val == NULL) {
+ return false;
+ }
- databuf = string_term_tdb_data(valstr);
- DEBUG(10, ("Adding cache entry with key = %s; value = %s and timeout ="
- " %s (%d seconds %s)\n", keystr, value,ctime(&timeout),
+ DEBUG(10, ("Adding cache entry with key=[%s] and timeout="
+ "[%s] (%d seconds %s)\n", keystr,
+ timestring(talloc_tos(), timeout),
(int)(timeout - time(NULL)),
timeout > time(NULL) ? "ahead" : "in the past"));
- ret = tdb_store_bystring(cache, keystr, databuf, 0);
- SAFE_FREE(valstr);
+ ret = tdb_store_bystring(
+ cache_notrans->tdb, keystr,
+ make_tdb_data((uint8_t *)val, talloc_array_length(val)),
+ 0);
+ TALLOC_FREE(val);
+
+ if (ret != 0) {
+ return false;
+ }
+
+ /*
+ * Every 100 writes within a single process, stabilize the cache with
+ * a transaction. This is done to prevent a single transaction to
+ * become huge and chew lots of memory.
+ */
+ writecount += 1;
+ if (writecount > lp_parm_int(-1, "gencache", "stabilize_count", 100)) {
+ gencache_stabilize();
+ writecount = 0;
+ goto done;
+ }
+
+ /*
+ * Every 5 minutes, call gencache_stabilize() to not let grow
+ * gencache_notrans.tdb too large.
+ */
+
+ last_stabilize = 0;
+ tdb_parse_record(cache_notrans->tdb, last_stabilize_key(),
+ last_stabilize_parser, &last_stabilize);
+
+ if ((last_stabilize
+ + lp_parm_int(-1, "gencache", "stabilize_interval", 300))
+ < time(NULL)) {
+ gencache_stabilize();
+ }
+
+done:
return ret == 0;
}
bool gencache_del(const char *keystr)
{
- int ret;
+ bool exists, was_expired;
+ bool ret = false;
+ DATA_BLOB value;
if (keystr == NULL) {
return false;
if (!gencache_init()) return False;
- DEBUG(10, ("Deleting cache entry (key = %s)\n", keystr));
- ret = tdb_delete_bystring(cache, keystr);
+ DEBUG(10, ("Deleting cache entry (key=[%s])\n", keystr));
- return ret == 0;
+ /*
+ * We delete an element by setting its timeout to 0. This way we don't
+ * have to do a transaction on gencache.tdb every time we delete an
+ * element.
+ */
+
+ exists = gencache_get_data_blob(keystr, NULL, &value, NULL,
+ &was_expired);
+
+ if (!exists && was_expired) {
+ /*
+ * gencache_get_data_blob has implicitly deleted this
+ * entry, so we have to return success here.
+ */
+ return true;
+ }
+
+ if (exists) {
+ data_blob_free(&value);
+ ret = gencache_set(keystr, "", 0);
+ }
+ return ret;
}
+static bool gencache_pull_timeout(char *val, time_t *pres, char **pendptr)
+{
+ time_t res;
+ char *endptr;
-/**
- * Get existing entry from the cache file.
- *
- * @param keystr string that represents a key of this entry
- * @param valstr buffer that is allocated and filled with the entry value
- * buffer's disposing must be done outside
- * @param timeout pointer to a time_t that is filled with entry's
- * timeout
- *
- * @retval true when entry is successfuly fetched
- * @retval False for failure
- **/
+ if (val == NULL) {
+ return false;
+ }
+
+ res = strtol(val, &endptr, 10);
-bool gencache_get(const char *keystr, char **valstr, time_t *timeout)
+ if ((endptr == NULL) || (*endptr != '/')) {
+ DEBUG(2, ("Invalid gencache data format: %s\n", val));
+ return false;
+ }
+ if (pres != NULL) {
+ *pres = res;
+ }
+ if (pendptr != NULL) {
+ *pendptr = endptr;
+ }
+ return true;
+}
+
+struct gencache_parse_state {
+ void (*parser)(time_t timeout, DATA_BLOB blob, void *private_data);
+ void *private_data;
+ bool is_memcache;
+};
+
+static int gencache_parse_fn(TDB_DATA key, TDB_DATA data, void *private_data)
{
- TDB_DATA databuf;
+ struct gencache_parse_state *state;
+ DATA_BLOB blob;
time_t t;
char *endptr;
+ bool ret;
+
+ if (data.dptr == NULL) {
+ return -1;
+ }
+ ret = gencache_pull_timeout((char *)data.dptr, &t, &endptr);
+ if (!ret) {
+ return -1;
+ }
+ state = (struct gencache_parse_state *)private_data;
+ blob = data_blob_const(
+ endptr+1, data.dsize - PTR_DIFF(endptr+1, data.dptr));
+ state->parser(t, blob, state->private_data);
+
+ if (!state->is_memcache) {
+ memcache_add(NULL, GENCACHE_RAM,
+ data_blob_const(key.dptr, key.dsize),
+ data_blob_const(data.dptr, data.dsize));
+ }
+
+ return 0;
+}
+
+bool gencache_parse(const char *keystr,
+ void (*parser)(time_t timeout, DATA_BLOB blob,
+ void *private_data),
+ void *private_data)
+{
+ struct gencache_parse_state state;
+ TDB_DATA key = string_term_tdb_data(keystr);
+ DATA_BLOB memcache_val;
+ int ret;
if (keystr == NULL) {
return false;
}
-
+ if (tdb_data_cmp(key, last_stabilize_key()) == 0) {
+ return false;
+ }
if (!gencache_init()) {
- return False;
+ return false;
}
- databuf = tdb_fetch_bystring(cache, keystr);
-
- if (databuf.dptr == NULL) {
- DEBUG(10, ("Cache entry with key = %s couldn't be found\n",
- keystr));
- return False;
+ state.parser = parser;
+ state.private_data = private_data;
+
+ if (memcache_lookup(NULL, GENCACHE_RAM,
+ data_blob_const(key.dptr, key.dsize),
+ &memcache_val)) {
+ /*
+ * Make sure that nobody has changed the gencache behind our
+ * back.
+ */
+ int current_seqnum = tdb_get_seqnum(cache_notrans->tdb);
+ if (current_seqnum == cache_notrans_seqnum) {
+ /*
+ * Ok, our memcache is still current, use it without
+ * going to the tdb files.
+ */
+ state.is_memcache = true;
+ gencache_parse_fn(key, make_tdb_data(memcache_val.data,
+ memcache_val.length),
+ &state);
+ return true;
+ }
+ memcache_flush(NULL, GENCACHE_RAM);
+ cache_notrans_seqnum = current_seqnum;
}
- t = strtol((const char *)databuf.dptr, &endptr, 10);
+ state.is_memcache = false;
- if ((endptr == NULL) || (*endptr != '/')) {
- DEBUG(2, ("Invalid gencache data format: %s\n", databuf.dptr));
- SAFE_FREE(databuf.dptr);
- return False;
+ ret = tdb_parse_record(cache_notrans->tdb, key,
+ gencache_parse_fn, &state);
+ if (ret == 0) {
+ return true;
}
+ ret = tdb_parse_record(cache->tdb, key, gencache_parse_fn, &state);
+ return (ret == 0);
+}
- DEBUG(10, ("Returning %s cache entry: key = %s, value = %s, "
- "timeout = %s", t > time(NULL) ? "valid" :
- "expired", keystr, endptr+1, ctime(&t)));
-
- if (t <= time(NULL)) {
+struct gencache_get_data_blob_state {
+ TALLOC_CTX *mem_ctx;
+ DATA_BLOB *blob;
+ time_t timeout;
+ bool result;
+};
- /* We're expired, delete the entry */
- tdb_delete_bystring(cache, keystr);
+static void gencache_get_data_blob_parser(time_t timeout, DATA_BLOB blob,
+ void *private_data)
+{
+ struct gencache_get_data_blob_state *state =
+ (struct gencache_get_data_blob_state *)private_data;
- SAFE_FREE(databuf.dptr);
- return False;
+ if (timeout == 0) {
+ state->result = false;
+ return;
}
+ state->timeout = timeout;
- if (valstr) {
- *valstr = SMB_STRDUP(endptr+1);
- if (*valstr == NULL) {
- SAFE_FREE(databuf.dptr);
- DEBUG(0, ("strdup failed\n"));
- return False;
- }
+ if (state->blob == NULL) {
+ state->result = true;
+ return;
}
- SAFE_FREE(databuf.dptr);
-
- if (timeout) {
- *timeout = t;
+ *state->blob = data_blob_talloc(state->mem_ctx, blob.data,
+ blob.length);
+ if (state->blob->data == NULL) {
+ state->result = false;
+ return;
}
-
- return True;
-}
+ state->result = true;
+}
/**
* Get existing entry from the cache file.
*
* @param keystr string that represents a key of this entry
* @param blob DATA_BLOB that is filled with entry's blob
- * @param expired pointer to a bool that indicates whether the entry is expired
+ * @param timeout pointer to a time_t that is filled with entry's
+ * timeout
*
* @retval true when entry is successfuly fetched
* @retval False for failure
**/
-bool gencache_get_data_blob(const char *keystr, DATA_BLOB *blob, bool *expired)
+bool gencache_get_data_blob(const char *keystr, TALLOC_CTX *mem_ctx,
+ DATA_BLOB *blob,
+ time_t *timeout, bool *was_expired)
{
- TDB_DATA databuf;
- time_t t;
- char *blob_type;
- unsigned char *buf = NULL;
- bool ret = False;
- fstring valstr;
- int buflen = 0, len = 0, blob_len = 0;
- unsigned char *blob_buf = NULL;
+ struct gencache_get_data_blob_state state;
+ bool expired = false;
- if (keystr == NULL) {
- return false;
- }
+ state.result = false;
+ state.mem_ctx = mem_ctx;
+ state.blob = blob;
- if (!gencache_init()) {
- return False;
+ if (!gencache_parse(keystr, gencache_get_data_blob_parser, &state)) {
+ goto fail;
}
-
- databuf = tdb_fetch_bystring(cache, keystr);
- if (!databuf.dptr) {
- DEBUG(10,("Cache entry with key = %s couldn't be found\n",
- keystr));
- return False;
+ if (!state.result) {
+ goto fail;
+ }
+ if (state.timeout <= time(NULL)) {
+ /*
+ * We're expired, delete the entry. We can't use gencache_del
+ * here, because that uses gencache_get_data_blob for checking
+ * the existence of a record. We know the thing exists and
+ * directly store an empty value with 0 timeout.
+ */
+ gencache_set(keystr, "", 0);
+ expired = true;
+ goto fail;
+ }
+ if (timeout) {
+ *timeout = state.timeout;
}
- buf = (unsigned char *)databuf.dptr;
- buflen = databuf.dsize;
+ return True;
- len += tdb_unpack(buf+len, buflen-len, "fB",
- &valstr,
- &blob_len, &blob_buf);
- if (len == -1) {
- goto out;
+fail:
+ if (was_expired != NULL) {
+ *was_expired = expired;
+ }
+ if (state.result && state.blob) {
+ data_blob_free(state.blob);
}
+ return false;
+}
- t = strtol(valstr, &blob_type, 10);
+struct stabilize_state {
+ bool written;
+};
+static int stabilize_fn(struct tdb_context *tdb, TDB_DATA key, TDB_DATA val,
+ void *priv);
- if (strcmp(blob_type+1, BLOB_TYPE) != 0) {
- goto out;
- }
+static int wipe_fn(struct tdb_context *tdb, TDB_DATA key, TDB_DATA val,
+ void *priv);
- DEBUG(10,("Returning %s cache entry: key = %s, "
- "timeout = %s", t > time(NULL) ? "valid" :
- "expired", keystr, ctime(&t)));
+/**
+ * Stabilize gencache
+ *
+ * Migrate the clear-if-first gencache data to the stable,
+ * transaction-based gencache.tdb
+ */
- if (t <= time(NULL)) {
- /* We're expired */
- if (expired) {
- *expired = True;
- }
+bool gencache_stabilize(void)
+{
+ struct stabilize_state state;
+ int res;
+ char *now;
+
+ if (!gencache_init()) {
+ return false;
}
- if (blob) {
- *blob = data_blob(blob_buf, blob_len);
- if (!blob->data) {
- goto out;
+ res = tdb_transaction_start_nonblock(cache->tdb);
+ if (res != 0) {
+ if (tdb_error(cache->tdb) == TDB_ERR_NOLOCK)
+ {
+ /*
+ * Someone else already does the stabilize,
+ * this does not have to be done twice
+ */
+ return true;
}
+
+ DEBUG(10, ("Could not start transaction on gencache.tdb: "
+ "%s\n", tdb_errorstr_compat(cache->tdb)));
+ return false;
}
- ret = True;
- out:
- SAFE_FREE(blob_buf);
- SAFE_FREE(databuf.dptr);
+ res = tdb_lockall(cache_notrans->tdb);
+ if (res != 0) {
+ tdb_transaction_cancel(cache->tdb);
+ DEBUG(10, ("Could not get allrecord lock on "
+ "gencache_notrans.tdb: %s\n",
+ tdb_errorstr_compat(cache_notrans->tdb)));
+ return false;
+ }
- return ret;
-}
+ state.written = false;
-/**
- * Set an entry in the cache file. If there's no such
- * one, then add it.
- *
- * @param keystr string that represents a key of this entry
- * @param blob DATA_BLOB value being cached
- * @param timeout time when the value is expired
- *
- * @retval true when entry is successfuly stored
- * @retval false on failure
- **/
+ res = tdb_traverse(cache_notrans->tdb, stabilize_fn, &state);
+ if (res < 0) {
+ tdb_unlockall(cache_notrans->tdb);
+ tdb_transaction_cancel(cache->tdb);
+ return false;
+ }
-bool gencache_set_data_blob(const char *keystr, const DATA_BLOB *blob, time_t timeout)
-{
- bool ret = False;
- int tdb_ret;
- TDB_DATA databuf;
- char *valstr = NULL;
- unsigned char *buf = NULL;
- int len = 0, buflen = 0;
+ if (!state.written) {
+ tdb_unlockall(cache_notrans->tdb);
+ tdb_transaction_cancel(cache->tdb);
+ return true;
+ }
- if ((keystr == NULL) || (blob == NULL)) {
+ res = tdb_transaction_commit(cache->tdb);
+ if (res != 0) {
+ DEBUG(10, ("tdb_transaction_commit on gencache.tdb failed: "
+ "%s\n", tdb_errorstr_compat(cache->tdb)));
+ tdb_unlockall(cache_notrans->tdb);
return false;
}
- if (!gencache_init()) {
- return False;
+ res = tdb_traverse(cache_notrans->tdb, wipe_fn, NULL);
+ if (res < 0) {
+ DEBUG(10, ("tdb_traverse with wipe_fn on gencache_notrans.tdb "
+ "failed: %s\n",
+ tdb_errorstr_compat(cache_notrans->tdb)));
+ tdb_unlockall(cache_notrans->tdb);
+ return false;
}
- if (asprintf(&valstr, "%12u/%s", (int)timeout, BLOB_TYPE) == -1) {
- return False;
+ res = tdb_unlockall(cache_notrans->tdb);
+ if (res != 0) {
+ DEBUG(10, ("tdb_unlockall on gencache.tdb failed: "
+ "%s\n", tdb_errorstr_compat(cache->tdb)));
+ return false;
+ }
+
+ now = talloc_asprintf(talloc_tos(), "%d", (int)time(NULL));
+ if (now != NULL) {
+ tdb_store(cache_notrans->tdb, last_stabilize_key(),
+ string_term_tdb_data(now), 0);
+ TALLOC_FREE(now);
}
- again:
- len = 0;
+ return true;
+}
- len += tdb_pack(buf+len, buflen-len, "fB",
- valstr,
- blob->length, blob->data);
+static int stabilize_fn(struct tdb_context *tdb, TDB_DATA key, TDB_DATA val,
+ void *priv)
+{
+ struct stabilize_state *state = (struct stabilize_state *)priv;
+ int res;
+ time_t timeout;
- if (len == -1) {
- goto out;
+ if (tdb_data_cmp(key, last_stabilize_key()) == 0) {
+ return 0;
}
- if (buflen < len) {
- SAFE_FREE(buf);
- buf = SMB_MALLOC_ARRAY(unsigned char, len);
- if (!buf) {
- goto out;
+ if (!gencache_pull_timeout((char *)val.dptr, &timeout, NULL)) {
+ DEBUG(10, ("Ignoring invalid entry\n"));
+ return 0;
+ }
+ if ((timeout < time(NULL)) || (val.dsize == 0)) {
+ res = tdb_delete(cache->tdb, key);
+ if (res == 0) {
+ state->written = true;
+ } else if (tdb_error(cache->tdb) == TDB_ERR_NOEXIST) {
+ res = 0;
+ }
+ } else {
+ res = tdb_store(cache->tdb, key, val, 0);
+ if (res == 0) {
+ state->written = true;
}
- buflen = len;
- goto again;
}
- databuf = make_tdb_data(buf, len);
+ if (res != 0) {
+ DEBUG(10, ("Transfer to gencache.tdb failed: %s\n",
+ tdb_errorstr_compat(cache->tdb)));
+ return -1;
+ }
- DEBUG(10,("Adding cache entry with key = %s; "
- "blob size = %d and timeout = %s"
- "(%d seconds %s)\n", keystr, (int)databuf.dsize,
- ctime(&timeout), (int)(timeout - time(NULL)),
- timeout > time(NULL) ? "ahead" : "in the past"));
+ return 0;
+}
- tdb_ret = tdb_store_bystring(cache, keystr, databuf, 0);
- if (tdb_ret == 0) {
- ret = True;
+static int wipe_fn(struct tdb_context *tdb, TDB_DATA key, TDB_DATA val,
+ void *priv)
+{
+ int res;
+ bool ok;
+ time_t timeout;
+
+ res = tdb_data_cmp(key, last_stabilize_key());
+ if (res == 0) {
+ return 0;
}
- out:
- SAFE_FREE(valstr);
- SAFE_FREE(buf);
+ ok = gencache_pull_timeout((char *)val.dptr, &timeout, NULL);
+ if (!ok) {
+ DEBUG(10, ("Ignoring invalid entry\n"));
+ return 0;
+ }
- return ret;
+ res = tdb_delete(tdb, key);
+ if (res != 0) {
+ DEBUG(10, ("tdb_delete from gencache_notrans.tdb failed: "
+ "%s\n", tdb_errorstr_compat(cache_notrans->tdb)));
+ return -1;
+ }
+
+ return 0;
}
+
/**
- * Iterate through all entries which key matches to specified pattern
+ * Get existing entry from the cache file.
*
- * @param fn pointer to the function that will be supplied with each single
- * matching cache entry (key, value and timeout) as an arguments
- * @param data void pointer to an arbitrary data that is passed directly to the fn
- * function on each call
- * @param keystr_pattern pattern the existing entries' keys are matched to
+ * @param keystr string that represents a key of this entry
+ * @param valstr buffer that is allocated and filled with the entry value
+ * buffer's disposing must be done outside
+ * @param timeout pointer to a time_t that is filled with entry's
+ * timeout
*
+ * @retval true when entry is successfuly fetched
+ * @retval False for failure
**/
-struct gencache_iterate_state {
- void (*fn)(const char *key, const char *value, time_t timeout,
- void *priv);
+bool gencache_get(const char *keystr, TALLOC_CTX *mem_ctx, char **value,
+ time_t *ptimeout)
+{
+ DATA_BLOB blob;
+ bool ret = False;
+
+ ret = gencache_get_data_blob(keystr, mem_ctx, &blob, ptimeout, NULL);
+ if (!ret) {
+ return false;
+ }
+ if ((blob.data == NULL) || (blob.length == 0)) {
+ data_blob_free(&blob);
+ return false;
+ }
+ if (blob.data[blob.length-1] != '\0') {
+ /* Not NULL terminated, can't be a string */
+ data_blob_free(&blob);
+ return false;
+ }
+ if (value) {
+ /*
+ * talloc_move generates a type-punned warning here. As we
+ * leave the function immediately, do a simple talloc_steal.
+ */
+ *value = (char *)talloc_steal(mem_ctx, blob.data);
+ return true;
+ }
+ data_blob_free(&blob);
+ return true;
+}
+
+/**
+ * Set an entry in the cache file. If there's no such
+ * one, then add it.
+ *
+ * @param keystr string that represents a key of this entry
+ * @param value text representation value being cached
+ * @param timeout time when the value is expired
+ *
+ * @retval true when entry is successfuly stored
+ * @retval false on failure
+ **/
+
+bool gencache_set(const char *keystr, const char *value, time_t timeout)
+{
+ DATA_BLOB blob = data_blob_const(value, strlen(value)+1);
+ return gencache_set_data_blob(keystr, &blob, timeout);
+}
+
+struct gencache_iterate_blobs_state {
+ void (*fn)(const char *key, DATA_BLOB value,
+ time_t timeout, void *private_data);
const char *pattern;
- void *priv;
+ void *private_data;
+ bool in_persistent;
};
-static int gencache_iterate_fn(struct tdb_context *tdb, TDB_DATA key,
- TDB_DATA value, void *priv)
+static int gencache_iterate_blobs_fn(struct tdb_context *tdb, TDB_DATA key,
+ TDB_DATA data, void *priv)
{
- struct gencache_iterate_state *state =
- (struct gencache_iterate_state *)priv;
+ struct gencache_iterate_blobs_state *state =
+ (struct gencache_iterate_blobs_state *)priv;
char *keystr;
char *free_key = NULL;
- char *valstr;
- char *free_val = NULL;
- unsigned long u;
time_t timeout;
- char *timeout_endp;
+ char *endptr;
+
+ if (tdb_data_cmp(key, last_stabilize_key()) == 0) {
+ return 0;
+ }
+ if (state->in_persistent && tdb_exists(cache_notrans->tdb, key)) {
+ return 0;
+ }
if (key.dptr[key.dsize-1] == '\0') {
keystr = (char *)key.dptr;
} else {
/* ensure 0-termination */
- keystr = SMB_STRNDUP((char *)key.dptr, key.dsize);
+ keystr = talloc_strndup(talloc_tos(), (char *)key.dptr, key.dsize);
free_key = keystr;
+ if (keystr == NULL) {
+ goto done;
+ }
}
- if ((value.dptr == NULL) || (value.dsize <= TIMEOUT_LEN)) {
+ if (!gencache_pull_timeout((char *)data.dptr, &timeout, &endptr)) {
goto done;
}
+ endptr += 1;
if (fnmatch(state->pattern, keystr, 0) != 0) {
goto done;
}
- if (value.dptr[value.dsize-1] == '\0') {
- valstr = (char *)value.dptr;
- } else {
- /* ensure 0-termination */
- valstr = SMB_STRNDUP((char *)value.dptr, value.dsize);
- free_val = valstr;
- }
-
- u = strtoul(valstr, &timeout_endp, 10);
-
- if ((*timeout_endp != '/') || ((timeout_endp-valstr) != TIMEOUT_LEN)) {
- goto done;
- }
-
- timeout = u;
- timeout_endp += 1;
-
DEBUG(10, ("Calling function with arguments "
- "(key = %s, value = %s, timeout = %s)\n",
- keystr, timeout_endp, ctime(&timeout)));
- state->fn(keystr, timeout_endp, timeout, state->priv);
+ "(key=[%s], timeout=[%s])\n",
+ keystr, timestring(talloc_tos(), timeout)));
+
+ state->fn(keystr,
+ data_blob_const(endptr,
+ data.dsize - PTR_DIFF(endptr, data.dptr)),
+ timeout, state->private_data);
done:
- SAFE_FREE(free_key);
- SAFE_FREE(free_val);
+ TALLOC_FREE(free_key);
return 0;
}
-void gencache_iterate(void (*fn)(const char* key, const char *value, time_t timeout, void* dptr),
- void* data, const char* keystr_pattern)
+void gencache_iterate_blobs(void (*fn)(const char *key, DATA_BLOB value,
+ time_t timeout, void *private_data),
+ void *private_data, const char *pattern)
{
- struct gencache_iterate_state state;
+ struct gencache_iterate_blobs_state state;
- if ((fn == NULL) || (keystr_pattern == NULL)) {
+ if ((fn == NULL) || (pattern == NULL) || !gencache_init()) {
return;
}
- if (!gencache_init()) return;
-
- DEBUG(5, ("Searching cache keys with pattern %s\n", keystr_pattern));
+ DEBUG(5, ("Searching cache keys with pattern %s\n", pattern));
state.fn = fn;
- state.pattern = keystr_pattern;
- state.priv = data;
- tdb_traverse(cache, gencache_iterate_fn, &state);
+ state.pattern = pattern;
+ state.private_data = private_data;
+
+ state.in_persistent = false;
+ tdb_traverse(cache_notrans->tdb, gencache_iterate_blobs_fn, &state);
+
+ state.in_persistent = true;
+ tdb_traverse(cache->tdb, gencache_iterate_blobs_fn, &state);
}
-/********************************************************************
- lock a key
-********************************************************************/
+/**
+ * Iterate through all entries which key matches to specified pattern
+ *
+ * @param fn pointer to the function that will be supplied with each single
+ * matching cache entry (key, value and timeout) as an arguments
+ * @param data void pointer to an arbitrary data that is passed directly to the fn
+ * function on each call
+ * @param keystr_pattern pattern the existing entries' keys are matched to
+ *
+ **/
+
+struct gencache_iterate_state {
+ void (*fn)(const char *key, const char *value, time_t timeout,
+ void *priv);
+ void *private_data;
+};
-int gencache_lock_entry( const char *key )
+static void gencache_iterate_fn(const char *key, DATA_BLOB value,
+ time_t timeout, void *private_data)
{
- if (!gencache_init())
- return -1;
+ struct gencache_iterate_state *state =
+ (struct gencache_iterate_state *)private_data;
+ char *valstr;
+ char *free_val = NULL;
- return tdb_lock_bystring(cache, key);
-}
+ if (value.data[value.length-1] == '\0') {
+ valstr = (char *)value.data;
+ } else {
+ /* ensure 0-termination */
+ valstr = talloc_strndup(talloc_tos(), (char *)value.data, value.length);
+ free_val = valstr;
+ if (valstr == NULL) {
+ goto done;
+ }
+ }
-/********************************************************************
- unlock a key
-********************************************************************/
+ DEBUG(10, ("Calling function with arguments "
+ "(key=[%s], value=[%s], timeout=[%s])\n",
+ key, valstr, timestring(talloc_tos(), timeout)));
+
+ state->fn(key, valstr, timeout, state->private_data);
+
+ done:
+
+ TALLOC_FREE(free_val);
+}
-void gencache_unlock_entry( const char *key )
+void gencache_iterate(void (*fn)(const char *key, const char *value,
+ time_t timeout, void *dptr),
+ void *private_data, const char *pattern)
{
- if (!gencache_init())
- return;
+ struct gencache_iterate_state state;
- tdb_unlock_bystring(cache, key);
- return;
+ if (fn == NULL) {
+ return;
+ }
+ state.fn = fn;
+ state.private_data = private_data;
+ gencache_iterate_blobs(gencache_iterate_fn, &state, pattern);
}
git.samba.org / obnox / samba / samba-obnox.git / blobdiff