stats: some more performance graphs

Add an infrastructure for collecting performance-related data, use it in
some places. Add rendering of them to stats.lua.

There were two main goals: minimal impact on the normal code and normal
playback. So all these stats_* function calls either happen only during
initialization, or return immediately if no stats collection is going
on. That's why it does this lazily adding of stats entries etc. (a first
iteration made each stats entry an API thing, instead of just a single
stats_ctx, but I thought that was getting too intrusive in the "normal"
code, even if everything gets worse inside of stats.c).

You could get most of this information from various profilers (including
the extremely primitive --dump-stats thing in mpv), but this makes it
easier to see the most important information at once (at least in
theory), partially because we know best about the context of various
things.

Not very happy with this. It's all pretty primitive and dumb. At this
point I just wanted to get over with it, without necessarily having to
revisit it later, but with having my stupid statistics.

Somehow the code feels terrible. There are a lot of meh decisions in
there that could be better or worse (but mostly could be better), and it
just sucks but it's also trivial and uninteresting and does the job. I
guess I hate programming. It's so tedious and the result is always shit.
Anyway, enjoy.

1 files changed, 32 insertions, 1 deletions

diff --git a/player/lua.c b/player/lua.c
index c816118b8b..0c5a56ec14 100644
--- a/player/lua.c
+++ b/player/lua.c
@@ -36,6 +36,7 @@
 #include "options/m_property.h"
 #include "common/msg.h"
 #include "common/msg_control.h"
+#include "common/stats.h"
 #include "options/m_option.h"
 #include "input/input.h"
 #include "options/path.h"
@@ -88,6 +89,8 @@ struct script_ctx {
     struct mp_log *log;
     struct mpv_handle *client;
     struct MPContext *mpctx;
+    size_t lua_malloc_size;
+    struct stats_ctx *stats;
 };
 
 #if LUA_VERSION_NUM <= 501
@@ -156,6 +159,30 @@ static void steal_node_alloctions(void *tmp, mpv_node *node)
     talloc_steal(tmp, node_get_alloc(node));
 }
 
+// lua_Alloc compatible. Serves only to retrieve memory usage.
+static void *mp_lua_alloc(void *ud, void *ptr, size_t osize, size_t nsize)
+{
+    struct script_ctx *ctx = ud;
+
+    // Ah, what the fuck, screw whoever introduced this to Lua 5.2.
+    if (!ptr)
+        osize = 0;
+
+    if (nsize) {
+        ptr = realloc(ptr, nsize);
+        if (!ptr)
+            return NULL;
+    } else {
+        free(ptr);
+        ptr = NULL;
+    }
+
+    ctx->lua_malloc_size = ctx->lua_malloc_size - osize + nsize;
+    stats_size_value(ctx->stats, "mem", ctx->lua_malloc_size);
+
+    return ptr;
+}
+
 static struct script_ctx *get_ctx(lua_State *L)
 {
     lua_getfield(L, LUA_REGISTRYINDEX, "ctx");
@@ -396,14 +423,18 @@ static int load_lua(struct mp_script_args *args)
         .log = args->log,
         .filename = args->filename,
         .path = args->path,
+        .stats = stats_ctx_create(ctx, args->mpctx->global,
+                    mp_tprintf(80, "script/%s", mpv_client_name(args->client))),
     };
 
+    stats_register_thread_cputime(ctx->stats, "cpu");
+
     if (LUA_VERSION_NUM != 501 && LUA_VERSION_NUM != 502) {
         MP_FATAL(ctx, "Only Lua 5.1 and 5.2 are supported.\n");
         goto error_out;
     }
 
-    lua_State *L = ctx->state = luaL_newstate();
+    lua_State *L = ctx->state = lua_newstate(mp_lua_alloc, ctx);
     if (!L) {
         MP_FATAL(ctx, "Could not initialize Lua.\n");
         goto error_out;