[FFmpeg-devel,2/8] ffserver: Implement lua config file reader

diff --git a/configreader.c b/configreader.c
new file mode 100644
index 0000000..3580fc5
--- /dev/null
+++ b/configreader.c
@@ -0,0 +1,235 @@ 
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "configreader.h"
+#include "httpd.h"
+#include <stdio.h>
+#include <string.h>
+#include <lua.h>
+#include <lauxlib.h>
+#include <lualib.h>
+
+#include <libavutil/mem.h>
+#include <libavutil/error.h>
+
+const char *stream_format_names[] = { "mkv" };
+
+static struct HTTPDConfig *parsed_configs = NULL;
+
+void stream_free(struct StreamConfig *stream)
+{
+    if (stream->stream_name)
+        av_free(stream->stream_name);
+    if (stream->input_uri)
+        av_free(stream->input_uri);
+    if (stream->formats)
+        av_free(stream->formats);
+}
+
+void config_free(struct HTTPDConfig *config)
+{
+    int i;
+    if (config->server_name)
+        av_free(config->server_name);
+    if (config->bind_address)
+        av_free(config->bind_address);
+    if (config->streams) {
+        for (i = 0; i < config->nb_streams; i++)
+            stream_free(&config->streams[i]);
+        av_free(config->streams);
+    }
+}
+
+void config_dump(struct HTTPDConfig *config, FILE *stream) {
+    int i, j;
+    fprintf(stream, "======\nserver name: %s\nbind_address: %s\nport: %d\nnb_streams: %d\n",
+            config->server_name, config->bind_address, config->port, config->nb_streams);
+    for (i = 0; i < config->nb_streams; i++) {
+        fprintf(stream, "------\nstream_name: %s\ninput: %s\nformats: ",
+            config->streams[i].stream_name, config->streams[i].input_uri);
+        for (j = 0; j < config->streams[i].nb_formats; j++) {
+            fprintf(stream, "%s ", stream_format_names[config->streams[i].formats[j]]);
+        }
+        fprintf(stream, "\n");
+    }
+}
+
+int configs_parse(lua_State *L)
+{
+    int nb_configs = 0;
+    int nb_streams = 0;
+    int nb_formats = 0;
+    int index = 0;
+    const char *key;
+    struct HTTPDConfig *config;
+    struct StreamConfig *stream;
+
+    luaL_checktype(L, -1, LUA_TTABLE);
+    lua_pushnil(L);
+    
+    // iterate servers
+    while (lua_next(L, -2) != 0) {
+        nb_configs++;
+        parsed_configs = av_realloc(parsed_configs, nb_configs * sizeof(struct HTTPDConfig));
+        if (!parsed_configs) {
+            return luaL_error(L, "Error could not allocate memory for configs");
+        }
+        luaL_checktype(L, -2, LUA_TSTRING);
+        luaL_checktype(L, -1, LUA_TTABLE);
+        config = &parsed_configs[nb_configs - 1];
+        config->server_name = NULL;
+        config->bind_address = NULL;
+        config->port = -1;
+        config->accept_timeout = 1000;
+        config->streams = NULL;
+        config->nb_streams = 0;
+
+        config->server_name = av_strdup(lua_tostring(L, -2));
+        if (!config->server_name) {
+            return luaL_error(L, "Error could not allocate server name string");
+        }
+        lua_pushnil(L);
+        // iterate server properties
+        nb_streams = 0;
+        while(lua_next(L, -2) != 0) {
+            luaL_checktype(L, -2, LUA_TSTRING);
+            key = lua_tostring(L, -2);
+            if (!strncmp("bind_address", key, 12)) {
+                config->bind_address = av_strdup(lua_tostring(L, -1));
+                if (!config->bind_address) {
+                    return luaL_error(L, "Error could not allocate bind address string");
+                }
+            } else if (!strncmp("port", key, 4)) {
+                config->port = (int) lua_tonumber(L, -1);
+            } else {
+                // keys that are not "bind_address" or "port" are streams
+                luaL_checktype(L, -1, LUA_TTABLE);
+
+                nb_streams++;
+                config->streams = av_realloc(config->streams, nb_streams * sizeof(struct StreamConfig));
+                if (!config->streams) {
+                    return luaL_error(L, "Error could not allocate memory for streams");
+                }
+                stream = &config->streams[nb_streams - 1];
+                stream->input_uri = NULL;
+                stream->formats = NULL;
+                stream->nb_formats = 0;
+                stream->stream_name = av_strdup(lua_tostring(L, -2));
+                if (!stream->stream_name) {
+                    return luaL_error(L, "Error could not allocate stream name string");
+                }
+                lua_pushnil(L);
+                while(lua_next(L, -2) != 0) {
+                    luaL_checktype(L, -2, LUA_TSTRING);
+                    key = lua_tostring(L, -2);
+                    if (!strncmp("input", key, 5)) {
+                        stream->input_uri = av_strdup(lua_tostring(L, -1));
+                        if (!stream->input_uri) {
+                            return luaL_error(L, "Error could not allocate input_uri");
+                        }
+                    } else if (!strncmp("formats", key, 7)) {
+                        index = 1;
+                        nb_formats = 0;
+                        lua_pushnumber(L, index);
+                        while(1) {
+                            lua_gettable(L, -2);
+                            if (lua_isnil(L, -1))
+                                break;
+                            luaL_checktype(L, -1, LUA_TSTRING);
+                            stream->formats = av_realloc(stream->formats,
+                                                         (nb_formats + 1) * sizeof(enum StreamFormat));
+                            if (!stream->formats) {
+                                return luaL_error(L, "Error could not allocate stream formats");
+                            }
+                            key = lua_tostring(L, -1);
+                            if (!strncmp("mkv", key, 3)) {
+                                stream->formats[nb_formats++] = FMT_MATROSKA;
+                            } else {
+                                fprintf(stderr, "Warning unknown format (%s) in stream format configuration.\n",
+                                                                                                           key);
+                                av_realloc(stream->formats, nb_formats * sizeof(enum StreamFormat));
+                                if (!stream->formats) {
+                                    return luaL_error(L, "Error could not shrink stream formats");
+                                }
+                            }
+                            stream->nb_formats = nb_formats;
+                            lua_pop(L, 1);
+                            lua_pushnumber(L, ++index);
+                        }
+                        lua_pop(L, 1);
+                            
+                    } else {
+                        fprintf(stderr, "Warning unknown key (%s) in stream configuration.\n", key);
+                    }
+                    lua_pop(L, 1);
+                }
+                if (stream->nb_formats == 0)
+                    luaL_error(L, "No format specified for stream %s on server %s", stream->stream_name, config->server_name);
+            }
+            lua_pop(L, 1);
+        }
+        if (config->port == -1)
+            return luaL_error(L, "No port set for server: %s", config->server_name);
+        if (!config->bind_address)
+            return luaL_error(L, "No bind address set for server: %s", config->server_name);
+        config->nb_streams = nb_streams;
+        lua_pop(L, 1);
+    }
+    lua_pushnumber(L, nb_configs);
+    return 1;
+}
+
+
+int configs_read(struct HTTPDConfig **configs, const char *filename)
+{
+    int ret = 0;
+    int nb_configs = 0;
+    lua_State *L = luaL_newstate();
+    ret = luaL_loadfile(L, filename);
+    if (ret != 0) {
+        fprintf(stderr, "Unable to open config file: %s\n", lua_tostring(L, -1));
+        lua_close(L);
+        return AVERROR_INVALIDDATA;
+    }
+
+    ret = lua_pcall(L, 0, 0, 0);
+
+    if (ret != 0) {
+        fprintf(stderr, "Unable to read config file: %s\n", lua_tostring(L, -1));
+        lua_close(L);
+        return AVERROR_INVALIDDATA;
+    }
+
+    lua_pushcfunction(L, configs_parse);
+    lua_getglobal(L, "settings");
+
+    ret = lua_pcall(L, 1, 1, 0);
+
+    if (ret != 0) {
+        fprintf(stderr, "Unable to parse config file: %s\n", lua_tostring(L, -1));
+        lua_close(L);
+        return AVERROR_INVALIDDATA;
+    }
+
+    nb_configs = lua_tonumber(L, -1);
+
+    lua_close(L);
+    *configs = parsed_configs;
+    return nb_configs;
+}
+
diff --git a/configreader.h b/configreader.h
new file mode 100644
index 0000000..7842a45
--- /dev/null
+++ b/configreader.h
@@ -0,0 +1,47 @@ 
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef CONFIGREADER_H
+#define CONFIGREADER_H
+
+#include "httpd.h"
+
+/**
+ * Read configurations from a file using the json format. The configurations
+ * are allocated as an array at *configs. This has to be freed by the user.
+ *
+ * @param configs pointer to a pointer where configurations will be allocated.
+ * @param filename filename of the configuration to use.
+ * @return number of configurations read, a negative AVERROR code on error.
+ */
+int configs_read(struct HTTPDConfig **configs, const char *filename);
+
+/**
+ * Dump a configuration to a stream specified by the user.
+ * @param config pointer to a configuration
+ * @param stream output stream to be used to dump the config
+ */
+void config_dump(struct HTTPDConfig *config, FILE *stream);
+
+/**
+ * Free a configuration.
+ * @param config pointer to a configuration
+ */
+void config_free(struct HTTPDConfig *config);
+
+#endif