1 files changed, 149 insertions, 0 deletions
diff --git a/stream/cache_file.c b/stream/cache_file.c
new file mode 100644
index 0000000000..dfdd8390dc
--- /dev/null
+++ b/stream/cache_file.c
@@ -0,0 +1,149 @@
+/*
+ * This file is part of mpv.
+ *
+ * mpv 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.
+ *
+ * mpv 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 mpv.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stdio.h>
+#include <stdint.h>
+
+#include "common/common.h"
+#include "common/msg.h"
+
+#include "options/options.h"
+
+#include "stream.h"
+
+#define BLOCK_SIZE 1024LL
+#define BLOCK_ALIGN(p) ((p) & ~(BLOCK_SIZE - 1))
+
+struct priv {
+    struct stream *original;
+    FILE *cache_file;
+    uint8_t *block_bits;    // 1 bit for each BLOCK_SIZE, whether block was read
+    int64_t size;           // currently known size
+    int64_t max_size;       // max. size for block_bits and cache_file
+};
+
+static bool test_bit(struct priv *p, int64_t pos)
+{
+    if (pos < 0 || pos >= p->size)
+        return false;
+    size_t block = pos / BLOCK_SIZE;
+    return p->block_bits[block / 8] & (1 << (block % 8));
+}
+
+static void set_bit(struct priv *p, int64_t pos, bool bit)
+{
+    if (pos < 0 || pos >= p->size)
+        return;
+    size_t block = pos / BLOCK_SIZE;
+    unsigned int m = (1 << (block % 8));
+    p->block_bits[block / 8] = (p->block_bits[block / 8] & ~m) | (bit ? m : 0);
+}
+
+static int fill_buffer(stream_t *s, char *buffer, int max_len)
+{
+    struct priv *p = s->priv;
+    if (s->pos < 0)
+        return -1;
+    if (s->pos >= p->max_size) {
+        if (stream_seek(p->original, s->pos) < 1)
+            return -1;
+        return stream_read(p->original, buffer, max_len);
+    }
+    // Size of file changes -> invalidate last block
+    if (s->pos >= p->size - BLOCK_SIZE) {
+        int64_t new_size = -1;
+        stream_control(s, STREAM_CTRL_GET_SIZE, &new_size);
+        if (new_size != p->size)
+            set_bit(p, BLOCK_ALIGN(p->size), 0);
+        p->size = MPMIN(p->max_size, new_size);
+    }
+    int64_t aligned = BLOCK_ALIGN(s->pos);
+    if (!test_bit(p, aligned)) {
+        char tmp[BLOCK_SIZE];
+        stream_seek(p->original, aligned);
+        int r = stream_read(p->original, tmp, BLOCK_SIZE);
+        if (r < BLOCK_SIZE) {
+            if (p->size < 0) {
+                MP_WARN(s, "suspected EOF\n");
+            } else if (aligned + r < p->size) {
+                MP_ERR(s, "unexpected EOF\n");
+                return -1;
+            }
+        }
+        if (fseeko(p->cache_file, aligned, SEEK_SET))
+            return -1;
+        if (fwrite(tmp, r, 1, p->cache_file) != 1)
+            return -1;
+        set_bit(p, aligned, 1);
+    }
+    if (fseeko(p->cache_file, s->pos, SEEK_SET))
+        return -1;
+    // align/limit to blocks
+    max_len = MPMIN(max_len, BLOCK_SIZE - (s->pos % BLOCK_SIZE));
+    // Limit to max. known file size
+    max_len = MPMIN(max_len, p->size - s->pos);
+    return fread(buffer, 1, max_len, p->cache_file);
+}
+
+static int seek(stream_t *s, int64_t newpos)
+{
+    return 1;
+}
+
+static int control(stream_t *s, int cmd, void *arg)
+{
+    struct priv *p = s->priv;
+    return stream_control(p->original, cmd, arg);
+}
+
+static void s_close(stream_t *s)
+{
+    struct priv *p = s->priv;
+    if (p->cache_file)
+        fclose(p->cache_file);
+    talloc_free(p);
+}
+
+// return 1 on success, 0 if disabled, -1 on error
+int stream_file_cache_init(stream_t *cache, stream_t *stream,
+                           struct mp_cache_opts *opts)
+{
+    if (!opts->file || !opts->file[0] || opts->file_max < 1)
+        return 0;
+
+    FILE *file = fopen(opts->file, "wb+");
+    if (!file) {
+        MP_ERR(cache, "can't open cache file '%s'\n", opts->file);
+        return -1;
+    }
+
+    struct priv *p = talloc_zero(NULL, struct priv);
+
+    cache->priv = p;
+    p->original = stream;
+    p->cache_file = file;
+    p->max_size = opts->file_max * 1024LL;
+
+    // file_max can be INT_MAX, so this is at most about 256MB
+    p->block_bits = talloc_zero_size(p, (p->max_size / BLOCK_SIZE + 1) / 8 + 1);
+
+    cache->seek = seek;
+    cache->fill_buffer = fill_buffer;
+    cache->control = control;
+    cache->close = s_close;
+
+    return 1;
+}