--- /dev/null
+/*
+ Unix SMB/CIFS implementation.
+ stat cache code
+ Copyright (C) Andrew Tridgell 1992-2000
+ Copyright (C) Jeremy Allison 1999-2004
+ Copyright (C) Andrew Bartlett <abartlet@samba.org> 2003
+
+ 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
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+
+/****************************************************************************
+ Stat cache code used in unix_convert.
+*****************************************************************************/
+
+static TDB_CONTEXT *tdb_stat_cache;
+
+/**
+ * Add an entry into the stat cache.
+ *
+ * @param full_orig_name The original name as specified by the client
+ * @param orig_translated_path The name on our filesystem.
+ *
+ * @note Only the first strlen(orig_translated_path) characters are stored
+ * into the cache. This means that full_orig_name will be internally
+ * truncated.
+ *
+ */
+
+void stat_cache_add( const char *full_orig_name, const char *orig_translated_path, BOOL case_sensitive)
+{
+ char *translated_path;
+ size_t translated_path_length;
+ TDB_DATA data_val;
+ char *original_path;
+ size_t original_path_length;
+ size_t sc_size = lp_max_stat_cache_size();
+
+ if (!lp_stat_cache())
+ return;
+
+ if (sc_size && (tdb_stat_cache->map_size > sc_size*1024)) {
+ reset_stat_cache();
+ }
+
+ ZERO_STRUCT(data_val);
+
+ /*
+ * Don't cache trivial valid directory entries such as . and ..
+ */
+
+ if((*full_orig_name == '\0') || (full_orig_name[0] == '.' &&
+ ((full_orig_name[1] == '\0') ||
+ (full_orig_name[1] == '.' && full_orig_name[2] == '\0'))))
+ return;
+
+ /*
+ * If we are in case insentive mode, we don't need to
+ * store names that need no translation - else, it
+ * would be a waste.
+ */
+
+ if(case_sensitive && (strcmp(full_orig_name, orig_translated_path) == 0))
+ return;
+
+ /*
+ * Remove any trailing '/' characters from the
+ * translated path.
+ */
+
+ translated_path = SMB_STRDUP(orig_translated_path);
+ if (!translated_path)
+ return;
+
+ translated_path_length = strlen(translated_path);
+
+ if(translated_path[translated_path_length-1] == '/') {
+ translated_path[translated_path_length-1] = '\0';
+ translated_path_length--;
+ }
+
+ if(case_sensitive) {
+ original_path = SMB_STRDUP(full_orig_name);
+ } else {
+ original_path = strdup_upper(full_orig_name);
+ }
+
+ if (!original_path) {
+ SAFE_FREE(translated_path);
+ return;
+ }
+
+ original_path_length = strlen(original_path);
+
+ if(original_path[original_path_length-1] == '/') {
+ original_path[original_path_length-1] = '\0';
+ original_path_length--;
+ }
+
+ if (original_path_length != translated_path_length) {
+ if (original_path_length < translated_path_length) {
+ DEBUG(0, ("OOPS - tried to store stat cache entry for weird length paths [%s] %lu and [%s] %lu)!\n",
+ original_path, (unsigned long)original_path_length, translated_path, (unsigned long)translated_path_length));
+ SAFE_FREE(original_path);
+ SAFE_FREE(translated_path);
+ return;
+ }
+
+ /* we only want to index by the first part of original_path,
+ up to the length of translated_path */
+
+ original_path[translated_path_length] = '\0';
+ original_path_length = translated_path_length;
+ }
+
+ /*
+ * New entry or replace old entry.
+ */
+
+ data_val.dsize = translated_path_length + 1;
+ data_val.dptr = translated_path;
+
+ if (tdb_store_bystring(tdb_stat_cache, original_path, data_val, TDB_REPLACE) != 0) {
+ DEBUG(0,("stat_cache_add: Error storing entry %s -> %s\n", original_path, translated_path));
+ } else {
+ DEBUG(5,("stat_cache_add: Added entry (%lx:size%x) %s -> %s\n",
+ (unsigned long)data_val.dptr, (unsigned int)data_val.dsize, original_path, translated_path));
+ }
+
+ SAFE_FREE(original_path);
+ SAFE_FREE(translated_path);
+}
+
+/**
+ * Look through the stat cache for an entry
+ *
+ * @param conn A connection struct to do the stat() with.
+ * @param name The path we are attempting to cache, modified by this routine
+ * to be correct as far as the cache can tell us
+ * @param dirpath The path as far as the stat cache told us.
+ * @param start A pointer into name, for where to 'start' in fixing the rest of the name up.
+ * @param psd A stat buffer, NOT from the cache, but just a side-effect.
+ *
+ * @return True if we translated (and did a scuccessful stat on) the entire name.
+ *
+ */
+
+BOOL stat_cache_lookup(connection_struct *conn, pstring name, pstring dirpath,
+ char **start, SMB_STRUCT_STAT *pst)
+{
+ char *chk_name;
+ size_t namelen;
+ BOOL sizechanged = False;
+ unsigned int num_components = 0;
+
+ if (!lp_stat_cache())
+ return False;
+
+ namelen = strlen(name);
+
+ *start = name;
+
+ DO_PROFILE_INC(statcache_lookups);
+
+ /*
+ * Don't lookup trivial valid directory entries.
+ */
+ if((*name == '\0') || (name[0] == '.' &&
+ ((name[1] == '\0') ||
+ (name[1] == '.' && name[1] == '\0'))))
+ return False;
+
+ if (conn->case_sensitive) {
+ chk_name = SMB_STRDUP(name);
+ if (!chk_name) {
+ DEBUG(0, ("stat_cache_lookup: strdup failed!\n"));
+ return False;
+ }
+
+ } else {
+ chk_name = strdup_upper(name);
+ if (!chk_name) {
+ DEBUG(0, ("stat_cache_lookup: strdup_upper failed!\n"));
+ return False;
+ }
+
+ /*
+ * In some language encodings the length changes
+ * if we uppercase. We need to treat this differently
+ * below.
+ */
+ if (strlen(chk_name) != namelen)
+ sizechanged = True;
+ }
+
+ while (1) {
+ TDB_DATA data_val;
+ char *sp;
+
+ data_val = tdb_fetch_bystring(tdb_stat_cache, chk_name);
+ if(data_val.dptr == NULL || data_val.dsize == 0) {
+ DEBUG(10,("stat_cache_lookup: lookup failed for name [%s]\n", chk_name ));
+ /*
+ * Didn't find it - remove last component for next try.
+ */
+ sp = strrchr_m(chk_name, '/');
+ if (sp) {
+ *sp = '\0';
+ /*
+ * Count the number of times we have done this,
+ * we'll need it when reconstructing the string.
+ */
+ if (sizechanged)
+ num_components++;
+
+ } else {
+ /*
+ * We reached the end of the name - no match.
+ */
+ DO_PROFILE_INC(statcache_misses);
+ SAFE_FREE(chk_name);
+ return False;
+ }
+ if((*chk_name == '\0') || (strcmp(chk_name, ".") == 0)
+ || (strcmp(chk_name, "..") == 0)) {
+ DO_PROFILE_INC(statcache_misses);
+ SAFE_FREE(chk_name);
+ return False;
+ }
+ } else {
+ BOOL retval;
+ char *translated_path = data_val.dptr;
+ size_t translated_path_length = data_val.dsize - 1;
+
+ DEBUG(10,("stat_cache_lookup: lookup succeeded for name [%s] -> [%s]\n", chk_name, translated_path ));
+ DO_PROFILE_INC(statcache_hits);
+ if(SMB_VFS_STAT(conn,translated_path, pst) != 0) {
+ /* Discard this entry - it doesn't exist in the filesystem. */
+ tdb_delete_bystring(tdb_stat_cache, chk_name);
+ SAFE_FREE(chk_name);
+ SAFE_FREE(data_val.dptr);
+ return False;
+ }
+
+ if (!sizechanged) {
+ memcpy(name, translated_path, MIN(sizeof(pstring)-1, translated_path_length));
+ } else if (num_components == 0) {
+ pstrcpy(name, translated_path);
+ } else {
+ sp = strnrchr_m(name, '/', num_components);
+ if (sp) {
+ pstring last_component;
+ pstrcpy(last_component, sp);
+ pstrcpy(name, translated_path);
+ pstrcat(name, last_component);
+ } else {
+ pstrcpy(name, translated_path);
+ }
+ }
+
+ /* set pointer for 'where to start' on fixing the rest of the name */
+ *start = &name[translated_path_length];
+ if(**start == '/')
+ ++*start;
+
+ pstrcpy(dirpath, translated_path);
+ retval = (namelen == translated_path_length) ? True : False;
+ SAFE_FREE(chk_name);
+ SAFE_FREE(data_val.dptr);
+ return retval;
+ }
+ }
+}
+
+/***************************************************************
+ Compute a hash value based on a string key value.
+ The function returns the bucket index number for the hashed key.
+ JRA. Use a djb-algorithm hash for speed.
+***************************************************************/
+
+u32 fast_string_hash(TDB_DATA *key)
+{
+ u32 n = 0;
+ const char *p;
+ for (p = key->dptr; *p != '\0'; p++) {
+ n = ((n << 5) + n) ^ (u32)(*p);
+ }
+ return n;
+}
+
+/***************************************************************************
+ Initializes or clears the stat cache.
+**************************************************************************/
+
+BOOL reset_stat_cache( void )
+{
+ if (!lp_stat_cache())
+ return True;
+
+ if (tdb_stat_cache) {
+ tdb_close(tdb_stat_cache);
+ }
+
+ /* Create the in-memory tdb using our custom hash function. */
+ tdb_stat_cache = tdb_open_ex("statcache", 1031, TDB_INTERNAL,
+ (O_RDWR|O_CREAT), 0644, NULL, fast_string_hash);
+
+ if (!tdb_stat_cache)
+ return False;
+ return True;
+}
projects / samba / blobdiff