client API: add stream_cb API for user-defined stream implementations

Based on #2630. Some heavy changes by committer.

Signed-off-by: wm4 <wm4@nowhere>

1 files changed, 108 insertions, 0 deletions

diff --git a/stream/stream_cb.c b/stream/stream_cb.c
new file mode 100644
index 0000000000..4496e63255
--- /dev/null
+++ b/stream/stream_cb.c
@@ -0,0 +1,108 @@
+#include "config.h"
+
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "osdep/io.h"
+
+#include "common/common.h"
+#include "common/msg.h"
+#include "common/global.h"
+#include "stream.h"
+#include "options/m_option.h"
+#include "options/path.h"
+#include "player/client.h"
+#include "libmpv/stream_cb.h"
+
+struct priv {
+    mpv_stream_cb_info info;
+};
+
+static int fill_buffer(stream_t *s, char *buffer, int max_len)
+{
+    struct priv *p = s->priv;
+    return (int)p->info.read_fn(p->info.cookie, buffer, (size_t)max_len);
+}
+
+static int seek(stream_t *s, int64_t newpos)
+{
+    struct priv *p = s->priv;
+    return (int)p->info.seek_fn(p->info.cookie, newpos) >= 0;
+}
+
+static int control(stream_t *s, int cmd, void *arg)
+{
+    struct priv *p = s->priv;
+    switch (cmd) {
+    case STREAM_CTRL_GET_SIZE: {
+        if (!p->info.size_fn)
+            break;
+        int64_t size = p->info.size_fn(p->info.cookie);
+        if (size >= 0) {
+            *(int64_t *)arg = size;
+            return 1;
+        }
+        break;
+    }
+    }
+    return STREAM_UNSUPPORTED;
+}
+
+static void s_close(stream_t *s)
+{
+    struct priv *p = s->priv;
+    p->info.close_fn(p->info.cookie);
+}
+
+static int open_cb(stream_t *stream)
+{
+    struct priv *p = talloc_ptrtype(stream, p);
+    stream->priv = p;
+
+    bstr bproto = mp_split_proto(bstr0(stream->url), NULL);
+    char *proto = bstrto0(stream, bproto);
+
+    void *user_data;
+    mpv_stream_cb_open_ro_fn open_fn;
+
+    if (!mp_streamcb_lookup(stream->global, proto, &user_data, &open_fn))
+        return STREAM_UNSUPPORTED;
+
+    mpv_stream_cb_info info = {0};
+
+    int r = open_fn(user_data, stream->url, &info);
+    if (r < 0) {
+        if (r != MPV_ERROR_LOADING_FAILED)
+            MP_WARN(stream, "unknown error from user callback\n");
+        return STREAM_ERROR;
+    }
+
+    if (!info.read_fn || !info.close_fn) {
+        MP_FATAL(stream, "required read_fn or close_fn callbacks not set.\n");
+        return STREAM_ERROR;
+    }
+
+    p->info = info;
+
+    if (p->info.seek_fn && p->info.seek_fn(p->info.cookie, 0) >= 0) {
+        stream->seek = seek;
+        stream->seekable = true;
+    }
+    stream->fast_skip = true;
+    stream->fill_buffer = fill_buffer;
+    stream->control = control;
+    stream->read_chunk = 64 * 1024;
+    stream->close = s_close;
+
+    return STREAM_OK;
+}
+
+const stream_info_t stream_info_cb = {
+    .name = "stream_callback",
+    .open = open_cb,
+    .protocols = (const char*const[]){ "*", NULL },
+};