disk_cache: move evict_lru_item() to an OS specific helper
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6197>
diff --git a/src/util/disk_cache.c b/src/util/disk_cache.c
index 943141c..a6f6f05 100644
--- a/src/util/disk_cache.c
+++ b/src/util/disk_cache.c
@@ -317,189 +317,6 @@
free(dir);
}
-/* Given a directory path and predicate function, find the entry with
- * the oldest access time in that directory for which the predicate
- * returns true.
- *
- * Returns: A malloc'ed string for the path to the chosen file, (or
- * NULL on any error). The caller should free the string when
- * finished.
- */
-static char *
-choose_lru_file_matching(const char *dir_path,
- bool (*predicate)(const char *dir_path,
- const struct stat *,
- const char *, const size_t))
-{
- DIR *dir;
- struct dirent *entry;
- char *filename;
- char *lru_name = NULL;
- time_t lru_atime = 0;
-
- dir = opendir(dir_path);
- if (dir == NULL)
- return NULL;
-
- while (1) {
- entry = readdir(dir);
- if (entry == NULL)
- break;
-
- struct stat sb;
- if (fstatat(dirfd(dir), entry->d_name, &sb, 0) == 0) {
- if (!lru_atime || (sb.st_atime < lru_atime)) {
- size_t len = strlen(entry->d_name);
-
- if (!predicate(dir_path, &sb, entry->d_name, len))
- continue;
-
- char *tmp = realloc(lru_name, len + 1);
- if (tmp) {
- lru_name = tmp;
- memcpy(lru_name, entry->d_name, len + 1);
- lru_atime = sb.st_atime;
- }
- }
- }
- }
-
- if (lru_name == NULL) {
- closedir(dir);
- return NULL;
- }
-
- if (asprintf(&filename, "%s/%s", dir_path, lru_name) < 0)
- filename = NULL;
-
- free(lru_name);
- closedir(dir);
-
- return filename;
-}
-
-/* Is entry a regular file, and not having a name with a trailing
- * ".tmp"
- */
-static bool
-is_regular_non_tmp_file(const char *path, const struct stat *sb,
- const char *d_name, const size_t len)
-{
- if (!S_ISREG(sb->st_mode))
- return false;
-
- if (len >= 4 && strcmp(&d_name[len-4], ".tmp") == 0)
- return false;
-
- return true;
-}
-
-/* Returns the size of the deleted file, (or 0 on any error). */
-static size_t
-unlink_lru_file_from_directory(const char *path)
-{
- struct stat sb;
- char *filename;
-
- filename = choose_lru_file_matching(path, is_regular_non_tmp_file);
- if (filename == NULL)
- return 0;
-
- if (stat(filename, &sb) == -1) {
- free (filename);
- return 0;
- }
-
- unlink(filename);
- free (filename);
-
- return sb.st_blocks * 512;
-}
-
-/* Is entry a directory with a two-character name, (and not the
- * special name of ".."). We also return false if the dir is empty.
- */
-static bool
-is_two_character_sub_directory(const char *path, const struct stat *sb,
- const char *d_name, const size_t len)
-{
- if (!S_ISDIR(sb->st_mode))
- return false;
-
- if (len != 2)
- return false;
-
- if (strcmp(d_name, "..") == 0)
- return false;
-
- char *subdir;
- if (asprintf(&subdir, "%s/%s", path, d_name) == -1)
- return false;
- DIR *dir = opendir(subdir);
- free(subdir);
-
- if (dir == NULL)
- return false;
-
- unsigned subdir_entries = 0;
- struct dirent *d;
- while ((d = readdir(dir)) != NULL) {
- if(++subdir_entries > 2)
- break;
- }
- closedir(dir);
-
- /* If dir only contains '.' and '..' it must be empty */
- if (subdir_entries <= 2)
- return false;
-
- return true;
-}
-
-static void
-evict_lru_item(struct disk_cache *cache)
-{
- char *dir_path;
-
- /* With a reasonably-sized, full cache, (and with keys generated
- * from a cryptographic hash), we can choose two random hex digits
- * and reasonably expect the directory to exist with a file in it.
- * Provides pseudo-LRU eviction to reduce checking all cache files.
- */
- uint64_t rand64 = rand_xorshift128plus(cache->seed_xorshift128plus);
- if (asprintf(&dir_path, "%s/%02" PRIx64 , cache->path, rand64 & 0xff) < 0)
- return;
-
- size_t size = unlink_lru_file_from_directory(dir_path);
-
- free(dir_path);
-
- if (size) {
- p_atomic_add(cache->size, - (uint64_t)size);
- return;
- }
-
- /* In the case where the random choice of directory didn't find
- * something, we choose the least recently accessed from the
- * existing directories.
- *
- * Really, the only reason this code exists is to allow the unit
- * tests to work, (which use an artificially-small cache to be able
- * to force a single cached item to be evicted).
- */
- dir_path = choose_lru_file_matching(cache->path,
- is_two_character_sub_directory);
- if (dir_path == NULL)
- return;
-
- size = unlink_lru_file_from_directory(dir_path);
-
- free(dir_path);
-
- if (size)
- p_atomic_add(cache->size, - (uint64_t)size);
-}
-
void
disk_cache_remove(struct disk_cache *cache, const cache_key key)
{
@@ -728,7 +545,7 @@
/* If the cache is too large, evict something else first. */
while (*dc_job->cache->size + dc_job->size > dc_job->cache->max_size &&
i < 8) {
- evict_lru_item(dc_job->cache);
+ disk_cache_evict_lru_item(dc_job->cache);
i++;
}
diff --git a/src/util/disk_cache_os.c b/src/util/disk_cache_os.c
index 48b79ac..3a146125 100644
--- a/src/util/disk_cache_os.c
+++ b/src/util/disk_cache_os.c
@@ -28,7 +28,9 @@
#else
+#include <dirent.h>
#include <errno.h>
+#include <inttypes.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
@@ -43,6 +45,7 @@
#include "util/disk_cache.h"
#include "util/disk_cache_os.h"
#include "util/ralloc.h"
+#include "util/rand_xor.h"
/* Create a directory named 'path' if it does not already exist.
*
@@ -104,6 +107,190 @@
return NULL;
}
+/* Given a directory path and predicate function, find the entry with
+ * the oldest access time in that directory for which the predicate
+ * returns true.
+ *
+ * Returns: A malloc'ed string for the path to the chosen file, (or
+ * NULL on any error). The caller should free the string when
+ * finished.
+ */
+static char *
+choose_lru_file_matching(const char *dir_path,
+ bool (*predicate)(const char *dir_path,
+ const struct stat *,
+ const char *, const size_t))
+{
+ DIR *dir;
+ struct dirent *entry;
+ char *filename;
+ char *lru_name = NULL;
+ time_t lru_atime = 0;
+
+ dir = opendir(dir_path);
+ if (dir == NULL)
+ return NULL;
+
+ while (1) {
+ entry = readdir(dir);
+ if (entry == NULL)
+ break;
+
+ struct stat sb;
+ if (fstatat(dirfd(dir), entry->d_name, &sb, 0) == 0) {
+ if (!lru_atime || (sb.st_atime < lru_atime)) {
+ size_t len = strlen(entry->d_name);
+
+ if (!predicate(dir_path, &sb, entry->d_name, len))
+ continue;
+
+ char *tmp = realloc(lru_name, len + 1);
+ if (tmp) {
+ lru_name = tmp;
+ memcpy(lru_name, entry->d_name, len + 1);
+ lru_atime = sb.st_atime;
+ }
+ }
+ }
+ }
+
+ if (lru_name == NULL) {
+ closedir(dir);
+ return NULL;
+ }
+
+ if (asprintf(&filename, "%s/%s", dir_path, lru_name) < 0)
+ filename = NULL;
+
+ free(lru_name);
+ closedir(dir);
+
+ return filename;
+}
+
+/* Is entry a regular file, and not having a name with a trailing
+ * ".tmp"
+ */
+static bool
+is_regular_non_tmp_file(const char *path, const struct stat *sb,
+ const char *d_name, const size_t len)
+{
+ if (!S_ISREG(sb->st_mode))
+ return false;
+
+ if (len >= 4 && strcmp(&d_name[len-4], ".tmp") == 0)
+ return false;
+
+ return true;
+}
+
+/* Returns the size of the deleted file, (or 0 on any error). */
+static size_t
+unlink_lru_file_from_directory(const char *path)
+{
+ struct stat sb;
+ char *filename;
+
+ filename = choose_lru_file_matching(path, is_regular_non_tmp_file);
+ if (filename == NULL)
+ return 0;
+
+ if (stat(filename, &sb) == -1) {
+ free (filename);
+ return 0;
+ }
+
+ unlink(filename);
+ free (filename);
+
+ return sb.st_blocks * 512;
+}
+
+/* Is entry a directory with a two-character name, (and not the
+ * special name of ".."). We also return false if the dir is empty.
+ */
+static bool
+is_two_character_sub_directory(const char *path, const struct stat *sb,
+ const char *d_name, const size_t len)
+{
+ if (!S_ISDIR(sb->st_mode))
+ return false;
+
+ if (len != 2)
+ return false;
+
+ if (strcmp(d_name, "..") == 0)
+ return false;
+
+ char *subdir;
+ if (asprintf(&subdir, "%s/%s", path, d_name) == -1)
+ return false;
+ DIR *dir = opendir(subdir);
+ free(subdir);
+
+ if (dir == NULL)
+ return false;
+
+ unsigned subdir_entries = 0;
+ struct dirent *d;
+ while ((d = readdir(dir)) != NULL) {
+ if(++subdir_entries > 2)
+ break;
+ }
+ closedir(dir);
+
+ /* If dir only contains '.' and '..' it must be empty */
+ if (subdir_entries <= 2)
+ return false;
+
+ return true;
+}
+
+/* Evict least recently used cache item */
+void
+disk_cache_evict_lru_item(struct disk_cache *cache)
+{
+ char *dir_path;
+
+ /* With a reasonably-sized, full cache, (and with keys generated
+ * from a cryptographic hash), we can choose two random hex digits
+ * and reasonably expect the directory to exist with a file in it.
+ * Provides pseudo-LRU eviction to reduce checking all cache files.
+ */
+ uint64_t rand64 = rand_xorshift128plus(cache->seed_xorshift128plus);
+ if (asprintf(&dir_path, "%s/%02" PRIx64 , cache->path, rand64 & 0xff) < 0)
+ return;
+
+ size_t size = unlink_lru_file_from_directory(dir_path);
+
+ free(dir_path);
+
+ if (size) {
+ p_atomic_add(cache->size, - (uint64_t)size);
+ return;
+ }
+
+ /* In the case where the random choice of directory didn't find
+ * something, we choose the least recently accessed from the
+ * existing directories.
+ *
+ * Really, the only reason this code exists is to allow the unit
+ * tests to work, (which use an artificially-small cache to be able
+ * to force a single cached item to be evicted).
+ */
+ dir_path = choose_lru_file_matching(cache->path,
+ is_two_character_sub_directory);
+ if (dir_path == NULL)
+ return;
+
+ size = unlink_lru_file_from_directory(dir_path);
+
+ free(dir_path);
+
+ if (size)
+ p_atomic_add(cache->size, - (uint64_t)size);
+}
+
/* Determine path for cache based on the first defined name as follows:
*
* $MESA_GLSL_CACHE_DIR
diff --git a/src/util/disk_cache_os.h b/src/util/disk_cache_os.h
index a8524ba..f6da300 100644
--- a/src/util/disk_cache_os.h
+++ b/src/util/disk_cache_os.h
@@ -76,6 +76,9 @@
char *
disk_cache_generate_cache_dir(void *mem_ctx);
+void
+disk_cache_evict_lru_item(struct disk_cache *cache);
+
bool
disk_cache_enabled(void);
