stream: create memory streams in more straightforward way

Instead of having to rely on the protocol matching, make a function that
creates a stream from a stream_info_t directly. Instead of going through
a weird indirection with STREAM_CTRL, add a direct argument for non-text
arguments to the open callback. Instead of creating a weird dummy
mpv_global, just pass an existing one from all callers. (The latter one
is just an artifact from the past, where mpv_global wasn't available
everywhere.)

Actually I just wanted a function that creates a stream without any of
that bullshit. This goal was slightly missed, since you still need this
heavy "constructor" just to setup a shitty struct with some shitty
callbacks.

demux/demux.c

@@ -2968,7 +2968,7 @@ void demux_close_stream(struct demuxer *demuxer)
 
     MP_VERBOSE(demuxer, "demuxer read all data; closing stream\n");
     free_stream(demuxer->stream);
-    demuxer->stream = open_memory_stream(NULL, 0); // dummy
+    demuxer->stream = stream_memory_open(demuxer->global, NULL, 0); // dummy
     demuxer->stream->cancel = demuxer->cancel;
     in->d_user->stream = demuxer->stream;
 }

demux/demux_lavf.c

@@ -396,7 +396,7 @@ static void convert_charset(struct demuxer *demuxer)
             data = conv;
     }
     if (data.start) {
-        priv->stream = open_memory_stream(data.start, data.len);
+        priv->stream = stream_memory_open(demuxer->global, data.start, data.len);
         priv->own_stream = true;
     }
     talloc_free(alloc);

demux/demux_libarchive.c

@@ -45,7 +45,8 @@ static int open_file(struct demuxer *demuxer, enum demux_check check)
     bstr probe = stream_peek(demuxer->stream, probe_size);
     if (probe.len == 0)
         return -1;
-    struct stream *probe_stream = open_memory_stream(probe.start, probe.len);
+    struct stream *probe_stream =
+        stream_memory_open(demuxer->global, probe.start, probe.len);
     struct mp_archive *mpa = mp_archive_new(mp_null_log, probe_stream, flags);
     bool ok = !!mpa;
     free_stream(probe_stream);

demux/demux_playlist.c

@@ -366,7 +366,7 @@ static int open_file(struct demuxer *demuxer, enum demux_check check)
     p->add_base = true;
 
     bstr probe_buf = stream_peek(demuxer->stream, PROBE_SIZE);
-    p->s = open_memory_stream(probe_buf.start, probe_buf.len);
+    p->s = stream_memory_open(demuxer->global, probe_buf.start, probe_buf.len);
     p->s->mime_type = demuxer->stream->mime_type;
     p->utf16 = stream_skip_bom(p->s);
     p->force = force;

stream/stream.c

@@ -213,10 +213,12 @@ static void stream_resize_buffer(struct stream *s, int new)
     }
 }
 
-static int open_internal(const stream_info_t *sinfo, const char *url, int flags,
+int stream_create_instance(const stream_info_t *sinfo, const char *url, int flags,
                            struct mp_cancel *c, struct mpv_global *global,
-                         struct stream **ret)
+                           void *arg, struct stream **ret)
 {
+    *ret = NULL;
+
     if (!sinfo->is_safe && (flags & STREAM_SAFE_ONLY))
         return STREAM_UNSAFE;
     if (!sinfo->is_network && (flags & STREAM_NETWORK_ONLY))
@@ -233,7 +235,11 @@ static int open_internal(const stream_info_t *sinfo, const char *url, int flags,
         return STREAM_NO_MATCH;
 
     stream_t *s = talloc_zero(NULL, stream_t);
+    if (flags & STREAM_SILENT) {
+        s->log = mp_null_log;
+    } else {
         s->log = mp_log_new(s, global->log, sinfo->name);
+    }
     s->info = sinfo;
     s->cancel = c;
     s->global = global;
@@ -242,21 +248,30 @@ static int open_internal(const stream_info_t *sinfo, const char *url, int flags,
     s->is_network = sinfo->is_network;
     s->mode = flags & (STREAM_READ | STREAM_WRITE);
 
-    if (global->config) {
     int opt;
     mp_read_option_raw(global, "access-references", &m_option_type_flag, &opt);
     s->access_references = opt;
-    }
 
     MP_VERBOSE(s, "Opening %s\n", url);
 
+    if (strlen(url) > INT_MAX / 8) {
+        MP_ERR(s, "URL too large.\n");
+        talloc_free(s);
+        return STREAM_ERROR;
+    }
+
     if ((s->mode & STREAM_WRITE) && !sinfo->can_write) {
         MP_DBG(s, "No write access implemented.\n");
         talloc_free(s);
         return STREAM_NO_MATCH;
     }
 
-    int r = (sinfo->open)(s);
+    int r = STREAM_UNSUPPORTED;
+    if (sinfo->open2) {
+        r = sinfo->open2(s, arg);
+    } else if (!arg) {
+        r = (sinfo->open)(s);
+    }
     if (r != STREAM_OK) {
         talloc_free(s);
         return r;
@@ -286,13 +301,11 @@ struct stream *stream_create(const char *url, int flags,
     struct stream *s = NULL;
     assert(url);
 
-    if (strlen(url) > INT_MAX / 8)
-        goto done;
-
     // Open stream proper
     bool unsafe = false;
     for (int i = 0; stream_list[i]; i++) {
-        int r = open_internal(stream_list[i], url, flags, c, global, &s);
+        int r = stream_create_instance(stream_list[i], url, flags, c, global,
+                                       NULL, &s);
         if (r == STREAM_OK)
             break;
         if (r == STREAM_NO_MATCH || r == STREAM_UNSUPPORTED)
@@ -617,18 +630,6 @@ void free_stream(stream_t *s)
     talloc_free(s);
 }
 
-stream_t *open_memory_stream(void *data, int len)
-{
-    assert(len >= 0);
-    struct mpv_global *dummy = talloc_zero(NULL, struct mpv_global);
-    dummy->log = mp_null_log;
-    stream_t *s = stream_open("memory://", dummy);
-    MP_HANDLE_OOM(s);
-    talloc_steal(s, dummy);
-    stream_control(s, STREAM_CTRL_SET_CONTENTS, &(bstr){data, len});
-    return s;
-}
-
 static uint16_t stream_read_word_endian(stream_t *s, bool big_endian)
 {
     unsigned int y = stream_read_char(s);

stream/stream.h

@@ -37,6 +37,7 @@
 // flags for stream_open_ext (this includes STREAM_READ and STREAM_WRITE)
 #define STREAM_SAFE_ONLY 4
 #define STREAM_NETWORK_ONLY 8
+#define STREAM_SILENT 16
 
 #define STREAM_UNSAFE -3
 #define STREAM_NO_MATCH -2
@@ -47,9 +48,6 @@
 enum stream_ctrl {
     STREAM_CTRL_GET_SIZE = 1,
 
-    // stream_memory.c
-    STREAM_CTRL_SET_CONTENTS,
-
     // Certain network protocols
     STREAM_CTRL_AVSEEK,
     STREAM_CTRL_HAS_AVSEEK,
@@ -72,6 +70,8 @@ typedef struct stream_info_st {
     const char *name;
     // opts is set from ->opts
     int (*open)(struct stream *st);
+    // Alternative to open(). Only either open() or open2() can be set.
+    int (*open2)(struct stream *st, void *arg);
     const char *const *protocols;
     bool can_write;     // correctly checks for READ/WRITE modes
     bool is_safe;       // opening is no security issue, even with remote provided URLs
@@ -165,15 +165,20 @@ struct bstr stream_read_file(const char *filename, void *talloc_ctx,
                              struct mpv_global *global, int max_size);
 int stream_control(stream_t *s, int cmd, void *arg);
 void free_stream(stream_t *s);
+int stream_create_instance(const stream_info_t *sinfo, const char *url, int flags,
+                           struct mp_cancel *c, struct mpv_global *global,
+                           void *arg, struct stream **ret);
 struct stream *stream_create(const char *url, int flags,
                              struct mp_cancel *c, struct mpv_global *global);
 struct stream *stream_open(const char *filename, struct mpv_global *global);
 stream_t *open_output_stream(const char *filename, struct mpv_global *global);
-stream_t *open_memory_stream(void *data, int len);
 
 void mp_url_unescape_inplace(char *buf);
 char *mp_url_escape(void *talloc_ctx, const char *s, const char *ok);
 
+// stream_memory.c
+struct stream *stream_memory_open(struct mpv_global *global, void *data, int len);
+
 // stream_file.c
 char *mp_file_url_to_filename(void *talloc_ctx, bstr url);
 char *mp_file_get_path(void *talloc_ctx, bstr url);

stream/stream_memory.c

@@ -17,6 +17,7 @@
 
 #include <libavutil/common.h>
 
+#include "common/common.h"
 #include "stream.h"
 
 struct priv {
@@ -42,20 +43,14 @@ static int seek(stream_t *s, int64_t newpos)
 static int control(stream_t *s, int cmd, void *arg)
 {
     struct priv *p = s->priv;
-    switch(cmd) {
+    if (cmd == STREAM_CTRL_GET_SIZE) {
-    case STREAM_CTRL_GET_SIZE:
         *(int64_t *)arg = p->data.len;
         return 1;
-    case STREAM_CTRL_SET_CONTENTS: ;
-        bstr *data = (bstr *)arg;
-        talloc_free(p->data.start);
-        p->data = bstrdup(s, *data);
-        return 1;
     }
     return STREAM_UNSUPPORTED;
 }
 
-static int open_f(stream_t *stream)
+static int open2(stream_t *stream, void *arg)
 {
     stream->fill_buffer = fill_buffer;
     stream->seek = seek;
@@ -71,7 +66,11 @@ static int open_f(stream_t *stream)
     bool use_hex = bstr_eatstart0(&data, "hex://");
     if (!use_hex)
         bstr_eatstart0(&data, "memory://");
-    stream_control(stream, STREAM_CTRL_SET_CONTENTS, &data);
+
+    if (arg)
+        data = *(bstr *)arg;
+
+    p->data = bstrdup(stream, data);
 
     if (use_hex && !bstr_decode_hex(stream, p->data, &p->data)) {
         MP_FATAL(stream, "Invalid data.\n");
@@ -83,6 +82,18 @@ static int open_f(stream_t *stream)
 
 const stream_info_t stream_info_memory = {
     .name = "memory",
-    .open = open_f,
+    .open2 = open2,
     .protocols = (const char*const[]){ "memory", "hex", NULL },
 };
+
+struct stream *stream_memory_open(struct mpv_global *global, void *data, int len)
+{
+    assert(len >= 0);
+
+    struct stream *s = NULL;
+    stream_create_instance(&stream_info_memory, "memory://",
+                           STREAM_READ | STREAM_SILENT, NULL, global,
+                           &(bstr){data, len}, &s);
+    MP_HANDLE_OOM(s);
+    return s;
+}