util: import cache.c/h from glsl

It's not dependent on GLSL and it can be useful for shader caches that don't
deal with GLSL.

v2: address review comments
v3: keep the other 3 lines in configure.ac

Reviewed-by: Emil Velikov <[email protected]>

1 files changed, 0 insertions, 710 deletions

diff --git a/src/compiler/glsl/cache.c b/src/compiler/glsl/cache.c
deleted file mode 100644
index e74c27d3000..00000000000
--- a/src/compiler/glsl/cache.c
+++ /dev/null
@@ -1,710 +0,0 @@
-/*
- * Copyright © 2014 Intel Corporation
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice (including the next
- * paragraph) shall be included in all copies or substantial portions of the
- * Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
- * IN THE SOFTWARE.
- */
-
-#include <ctype.h>
-#include <string.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <sys/file.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/mman.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <pwd.h>
-#include <errno.h>
-#include <dirent.h>
-
-#include "util/u_atomic.h"
-#include "util/mesa-sha1.h"
-#include "util/ralloc.h"
-#include "main/errors.h"
-
-#include "cache.h"
-
-/* Number of bits to mask off from a cache key to get an index. */
-#define CACHE_INDEX_KEY_BITS 16
-
-/* Mask for computing an index from a key. */
-#define CACHE_INDEX_KEY_MASK ((1 << CACHE_INDEX_KEY_BITS) - 1)
-
-/* The number of keys that can be stored in the index. */
-#define CACHE_INDEX_MAX_KEYS (1 << CACHE_INDEX_KEY_BITS)
-
-struct program_cache {
-   /* The path to the cache directory. */
-   char *path;
-
-   /* A pointer to the mmapped index file within the cache directory. */
-   uint8_t *index_mmap;
-   size_t index_mmap_size;
-
-   /* Pointer to total size of all objects in cache (within index_mmap) */
-   uint64_t *size;
-
-   /* Pointer to stored keys, (within index_mmap). */
-   uint8_t *stored_keys;
-
-   /* Maximum size of all cached objects (in bytes). */
-   uint64_t max_size;
-};
-
-/* Create a directory named 'path' if it does not already exist.
- *
- * Returns: 0 if path already exists as a directory or if created.
- *         -1 in all other cases.
- */
-static int
-mkdir_if_needed(char *path)
-{
-   struct stat sb;
-
-   /* If the path exists already, then our work is done if it's a
-    * directory, but it's an error if it is not.
-    */
-   if (stat(path, &sb) == 0) {
-      if (S_ISDIR(sb.st_mode)) {
-         return 0;
-      } else {
-         _mesa_warning(NULL,
-                       "Cannot use %s for shader cache (not a directory)"
-                       "---disabling.\n", path);
-         return -1;
-      }
-   }
-
-   int ret = mkdir(path, 0755);
-   if (ret == 0 || (ret == -1 && errno == EEXIST))
-     return 0;
-
-   _mesa_warning(NULL,
-                 "Failed to create %s for shader cache (%s)---disabling.\n",
-                 path, strerror(errno));
-
-   return -1;
-}
-
-/* Concatenate an existing path and a new name to form a new path.  If the new
- * path does not exist as a directory, create it then return the resulting
- * name of the new path (ralloc'ed off of 'ctx').
- *
- * Returns NULL on any error, such as:
- *
- *      <path> does not exist or is not a directory
- *      <path>/<name> exists but is not a directory
- *      <path>/<name> cannot be created as a directory
- */
-static char *
-concatenate_and_mkdir(void *ctx, char *path, char *name)
-{
-   char *new_path;
-   struct stat sb;
-
-   if (stat(path, &sb) != 0 || ! S_ISDIR(sb.st_mode))
-      return NULL;
-
-   new_path = ralloc_asprintf(ctx, "%s/%s", path, name);
-
-   if (mkdir_if_needed(new_path) == 0)
-      return new_path;
-   else
-      return NULL;
-}
-
-struct program_cache *
-cache_create(void)
-{
-   void *local;
-   struct program_cache *cache = NULL;
-   char *path, *max_size_str;
-   uint64_t max_size;
-   int fd = -1;
-   struct stat sb;
-   size_t size;
-
-   /* A ralloc context for transient data during this invocation. */
-   local = ralloc_context(NULL);
-   if (local == NULL)
-      goto fail;
-
-   /* At user request, disable shader cache entirely. */
-   if (getenv("MESA_GLSL_CACHE_DISABLE"))
-      goto fail;
-
-   /* Determine path for cache based on the first defined name as follows:
-    *
-    *   $MESA_GLSL_CACHE_DIR
-    *   $XDG_CACHE_HOME/mesa
-    *   <pwd.pw_dir>/.cache/mesa
-    */
-   path = getenv("MESA_GLSL_CACHE_DIR");
-   if (path && mkdir_if_needed(path) == -1) {
-      goto fail;
-   }
-
-   if (path == NULL) {
-      char *xdg_cache_home = getenv("XDG_CACHE_HOME");
-
-      if (xdg_cache_home) {
-         if (mkdir_if_needed(xdg_cache_home) == -1)
-            goto fail;
-
-         path = concatenate_and_mkdir(local, xdg_cache_home, "mesa");
-         if (path == NULL)
-            goto fail;
-      }
-   }
-
-   if (path == NULL) {
-      char *buf;
-      size_t buf_size;
-      struct passwd pwd, *result;
-
-      buf_size = sysconf(_SC_GETPW_R_SIZE_MAX);
-      if (buf_size == -1)
-         buf_size = 512;
-
-      /* Loop until buf_size is large enough to query the directory */
-      while (1) {
-         buf = ralloc_size(local, buf_size);
-
-         getpwuid_r(getuid(), &pwd, buf, buf_size, &result);
-         if (result)
-            break;
-
-         if (errno == ERANGE) {
-            ralloc_free(buf);
-            buf = NULL;
-            buf_size *= 2;
-         } else {
-            goto fail;
-         }
-      }
-
-      path = concatenate_and_mkdir(local, pwd.pw_dir, ".cache");
-      if (path == NULL)
-         goto fail;
-
-      path = concatenate_and_mkdir(local, path, "mesa");
-      if (path == NULL)
-         goto fail;
-   }
-
-   cache = ralloc(NULL, struct program_cache);
-   if (cache == NULL)
-      goto fail;
-
-   cache->path = ralloc_strdup(cache, path);
-   if (cache->path == NULL)
-      goto fail;
-
-   path = ralloc_asprintf(local, "%s/index", cache->path);
-   if (path == NULL)
-      goto fail;
-
-   fd = open(path, O_RDWR | O_CREAT | O_CLOEXEC, 0644);
-   if (fd == -1)
-      goto fail;
-
-   if (fstat(fd, &sb) == -1)
-      goto fail;
-
-   /* Force the index file to be the expected size. */
-   size = sizeof(*cache->size) + CACHE_INDEX_MAX_KEYS * CACHE_KEY_SIZE;
-   if (sb.st_size != size) {
-      if (ftruncate(fd, size) == -1)
-         goto fail;
-   }
-
-   /* We map this shared so that other processes see updates that we
-    * make.
-    *
-    * Note: We do use atomic addition to ensure that multiple
-    * processes don't scramble the cache size recorded in the
-    * index. But we don't use any locking to prevent multiple
-    * processes from updating the same entry simultaneously. The idea
-    * is that if either result lands entirely in the index, then
-    * that's equivalent to a well-ordered write followed by an
-    * eviction and a write. On the other hand, if the simultaneous
-    * writes result in a corrupt entry, that's not really any
-    * different than both entries being evicted, (since within the
-    * guarantees of the cryptographic hash, a corrupt entry is
-    * unlikely to ever match a real cache key).
-    */
-   cache->index_mmap = mmap(NULL, size, PROT_READ | PROT_WRITE,
-                            MAP_SHARED, fd, 0);
-   if (cache->index_mmap == MAP_FAILED)
-      goto fail;
-   cache->index_mmap_size = size;
-
-   close(fd);
-
-   cache->size = (uint64_t *) cache->index_mmap;
-   cache->stored_keys = cache->index_mmap + sizeof(uint64_t);
-
-   max_size = 0;
-
-   max_size_str = getenv("MESA_GLSL_CACHE_MAX_SIZE");
-   if (max_size_str) {
-      char *end;
-      max_size = strtoul(max_size_str, &end, 10);
-      if (end == max_size_str) {
-         max_size = 0;
-      } else {
-         while (*end && isspace(*end))
-            end++;
-         switch (*end) {
-         case 'K':
-         case 'k':
-            max_size *= 1024;
-            break;
-         case 'M':
-         case 'm':
-            max_size *= 1024*1024;
-            break;
-         case '\0':
-         case 'G':
-         case 'g':
-         default:
-            max_size *= 1024*1024*1024;
-            break;
-         }
-      }
-   }
-
-   /* Default to 1GB for maximum cache size. */
-   if (max_size == 0)
-      max_size = 1024*1024*1024;
-
-   cache->max_size = max_size;
-
-   ralloc_free(local);
-
-   return cache;
-
- fail:
-   if (fd != -1)
-      close(fd);
-   if (cache)
-      ralloc_free(cache);
-   ralloc_free(local);
-
-   return NULL;
-}
-
-void
-cache_destroy(struct program_cache *cache)
-{
-   munmap(cache->index_mmap, cache->index_mmap_size);
-
-   ralloc_free(cache);
-}
-
-/* Return a filename within the cache's directory corresponding to 'key'. The
- * returned filename is ralloced with 'cache' as the parent context.
- *
- * Returns NULL if out of memory.
- */
-static char *
-get_cache_file(struct program_cache *cache, cache_key key)
-{
-   char buf[41];
-
-   _mesa_sha1_format(buf, key);
-
-   return ralloc_asprintf(cache, "%s/%c%c/%s",
-                          cache->path, buf[0], buf[1], buf + 2);
-}
-
-/* Create the directory that will be needed for the cache file for \key.
- *
- * Obviously, the implementation here must closely match
- * _get_cache_file above.
-*/
-static void
-make_cache_file_directory(struct program_cache *cache, cache_key key)
-{
-   char *dir;
-   char buf[41];
-
-   _mesa_sha1_format(buf, key);
-
-   dir = ralloc_asprintf(cache, "%s/%c%c", cache->path, buf[0], buf[1]);
-
-   mkdir_if_needed(dir);
-
-   ralloc_free(dir);
-}
-
-/* Given a directory path and predicate function, count all entries in
- * that directory for which the predicate returns true. Then choose a
- * random entry from among those counted.
- *
- * 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_random_file_matching(const char *dir_path,
-                            bool (*predicate)(struct dirent *))
-{
-   DIR *dir;
-   struct dirent *entry;
-   unsigned int count, victim;
-   char *filename;
-
-   dir = opendir(dir_path);
-   if (dir == NULL)
-      return NULL;
-
-   count = 0;
-
-   while (1) {
-      entry = readdir(dir);
-      if (entry == NULL)
-         break;
-      if (! predicate(entry))
-         continue;
-
-      count++;
-   }
-
-   if (count == 0) {
-      closedir(dir);
-      return NULL;
-   }
-
-   victim = rand() % count;
-
-   rewinddir(dir);
-   count = 0;
-
-   while (1) {
-      entry = readdir(dir);
-      if (entry == NULL)
-         break;
-      if (! predicate(entry))
-         continue;
-      if (count == victim)
-         break;
-
-      count++;
-   }
-
-   if (entry == NULL) {
-      closedir(dir);
-      return NULL;
-   }
-
-   if (asprintf(&filename, "%s/%s", dir_path, entry->d_name) < 0)
-      filename = NULL;
-
-   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(struct dirent *entry)
-{
-   size_t len;
-
-   if (entry->d_type != DT_REG)
-      return false;
-
-   len = strlen (entry->d_name);
-   if (len >= 4 && strcmp(&entry->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_random_file_from_directory(const char *path)
-{
-   struct stat sb;
-   char *filename;
-
-   filename = choose_random_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_size;
-}
-
-/* Is entry a directory with a two-character name, (and not the
- * special name of "..")
- */
-static bool
-is_two_character_sub_directory(struct dirent *entry)
-{
-   if (entry->d_type != DT_DIR)
-      return false;
-
-   if (strlen(entry->d_name) != 2)
-      return false;
-
-   if (strcmp(entry->d_name, "..") == 0)
-      return false;
-
-   return true;
-}
-
-static void
-evict_random_item(struct program_cache *cache)
-{
-   const char hex[] = "0123456789abcde";
-   char *dir_path;
-   int a, b;
-   size_t size;
-
-   /* 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.
-    */
-   a = rand() % 16;
-   b = rand() % 16;
-
-   if (asprintf(&dir_path, "%s/%c%c", cache->path, hex[a], hex[b]) < 0)
-      return;
-
-   size = unlink_random_file_from_directory(dir_path);
-
-   free(dir_path);
-
-   if (size) {
-      p_atomic_add(cache->size, - size);
-      return;
-   }
-
-   /* In the case where the random choice of directory didn't find
-    * something, we choose randomly 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_random_file_matching(cache->path,
-                                          is_two_character_sub_directory);
-   if (dir_path == NULL)
-      return;
-
-   size = unlink_random_file_from_directory(dir_path);
-
-   free(dir_path);
-
-   if (size)
-      p_atomic_add(cache->size, - size);
-}
-
-void
-cache_put(struct program_cache *cache,
-          cache_key key,
-          const void *data,
-          size_t size)
-{
-   int fd = -1, fd_final = -1, err, ret;
-   size_t len;
-   char *filename = NULL, *filename_tmp = NULL;
-   const char *p = data;
-
-   filename = get_cache_file(cache, key);
-   if (filename == NULL)
-      goto done;
-
-   /* Write to a temporary file to allow for an atomic rename to the
-    * final destination filename, (to prevent any readers from seeing
-    * a partially written file).
-    */
-   filename_tmp = ralloc_asprintf(cache, "%s.tmp", filename);
-   if (filename_tmp == NULL)
-      goto done;
-
-   fd = open(filename_tmp, O_WRONLY | O_CLOEXEC | O_CREAT, 0644);
-
-   /* Make the two-character subdirectory within the cache as needed. */
-   if (fd == -1) {
-      if (errno != ENOENT)
-         goto done;
-
-      make_cache_file_directory(cache, key);
-
-      fd = open(filename_tmp, O_WRONLY | O_CLOEXEC | O_CREAT, 0644);
-      if (fd == -1)
-         goto done;
-   }
-
-   /* With the temporary file open, we take an exclusive flock on
-    * it. If the flock fails, then another process still has the file
-    * open with the flock held. So just let that file be responsible
-    * for writing the file.
-    */
-   err = flock(fd, LOCK_EX | LOCK_NB);
-   if (err == -1)
-      goto done;
-
-   /* Now that we have the lock on the open temporary file, we can
-    * check to see if the destination file already exists. If so,
-    * another process won the race between when we saw that the file
-    * didn't exist and now. In this case, we don't do anything more,
-    * (to ensure the size accounting of the cache doesn't get off).
-    */
-   fd_final = open(filename, O_RDONLY | O_CLOEXEC);
-   if (fd_final != -1)
-      goto done;
-
-   /* OK, we're now on the hook to write out a file that we know is
-    * not in the cache, and is also not being written out to the cache
-    * by some other process.
-    *
-    * Before we do that, if the cache is too large, evict something
-    * else first.
-    */
-   if (*cache->size + size > cache->max_size)
-      evict_random_item(cache);
-
-   /* Now, finally, write out the contents to the temporary file, then
-    * rename them atomically to the destination filename, and also
-    * perform an atomic increment of the total cache size.
-    */
-   for (len = 0; len < size; len += ret) {
-      ret = write(fd, p + len, size - len);
-      if (ret == -1) {
-         unlink(filename_tmp);
-         goto done;
-      }
-   }
-
-   rename(filename_tmp, filename);
-
-   p_atomic_add(cache->size, size);
-
-   /* This close finally releases the flock, (now that the final dile
-    * has been renamed into place and the size has been added).
-    */
-   close(fd);
-   fd = -1;
-
- done:
-   if (filename_tmp)
-      ralloc_free(filename_tmp);
-   if (filename)
-      ralloc_free(filename);
-   if (fd != -1)
-      close(fd);
-}
-
-void *
-cache_get(struct program_cache *cache, cache_key key, size_t *size)
-{
-   int fd = -1, ret, len;
-   struct stat sb;
-   char *filename = NULL;
-   uint8_t *data = NULL;
-
-   if (size)
-      *size = 0;
-
-   filename = get_cache_file(cache, key);
-   if (filename == NULL)
-      goto fail;
-
-   fd = open(filename, O_RDONLY | O_CLOEXEC);
-   if (fd == -1)
-      goto fail;
-
-   if (fstat(fd, &sb) == -1)
-      goto fail;
-
-   data = malloc(sb.st_size);
-   if (data == NULL)
-      goto fail;
-
-   for (len = 0; len < sb.st_size; len += ret) {
-      ret = read(fd, data + len, sb.st_size - len);
-      if (ret == -1)
-         goto fail;
-   }
-
-   ralloc_free(filename);
-   close(fd);
-
-   if (size)
-      *size = sb.st_size;
-
-   return data;
-
- fail:
-   if (data)
-      free(data);
-   if (filename)
-      ralloc_free(filename);
-   if (fd != -1)
-      close(fd);
-
-   return NULL;
-}
-
-void
-cache_put_key(struct program_cache *cache, cache_key key)
-{
-   uint32_t *key_chunk = (uint32_t *) key;
-   int i = *key_chunk & CACHE_INDEX_KEY_MASK;
-   unsigned char *entry;
-
-   entry = &cache->stored_keys[i + CACHE_KEY_SIZE];
-
-   memcpy(entry, key, CACHE_KEY_SIZE);
-}
-
-/* This function lets us test whether a given key was previously
- * stored in the cache with cache_put_key(). The implement is
- * efficient by not using syscalls or hitting the disk. It's not
- * race-free, but the races are benign. If we race with someone else
- * calling cache_put_key, then that's just an extra cache miss and an
- * extra recompile.
- */
-bool
-cache_has_key(struct program_cache *cache, cache_key key)
-{
-   uint32_t *key_chunk = (uint32_t *) key;
-   int i = *key_chunk & CACHE_INDEX_KEY_MASK;
-   unsigned char *entry;
-
-   entry = &cache->stored_keys[i + CACHE_KEY_SIZE];
-
-   return memcmp(entry, key, CACHE_KEY_SIZE) == 0;
-}