Fix bug #1426: Echo cancelation state blob is too big for being in linphonerc

The state of the echo canceler is stored in a file beside .linphonerc
The file is named .linphone.ecstate

coreapi/linphonecall.c

@@ -37,6 +37,8 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 #include "mediastreamer2/mseventqueue.h"
 #include "mediastreamer2/mssndcard.h"
 
+static const char EC_STATE_STORE[] = ".linphone.ecstate";
+
 static void linphone_call_stats_uninit(LinphoneCallStats *stats);
 
 #ifdef VIDEO_ENABLED
@@ -1544,13 +1546,14 @@ void linphone_call_init_audio_stream(LinphoneCall *call){
 	audio_stream_enable_gain_control(audiostream,TRUE);
 	if (linphone_core_echo_cancellation_enabled(lc)){
 		int len,delay,framesize;
-		const char *statestr=lp_config_get_string(lc->config,"sound","ec_state",NULL);
+		char *statestr=lp_config_read_relative_file(lc->config, EC_STATE_STORE);
 		len=lp_config_get_int(lc->config,"sound","ec_tail_len",0);
 		delay=lp_config_get_int(lc->config,"sound","ec_delay",0);
 		framesize=lp_config_get_int(lc->config,"sound","ec_framesize",0);
 		audio_stream_set_echo_canceller_params(audiostream,len,delay,framesize);
 		if (statestr && audiostream->ec){
 			ms_filter_call_method(audiostream->ec,MS_ECHO_CANCELLER_SET_STATE_STRING,(void*)statestr);
+			ms_free(statestr);
 		}
 	}
 	audio_stream_enable_automatic_gain_control(audiostream,linphone_core_agc_enabled(lc));
@@ -2286,7 +2289,7 @@ static void linphone_call_stop_audio_stream(LinphoneCall *call) {
 			ms_filter_call_method(call->audiostream->ec,MS_ECHO_CANCELLER_GET_STATE_STRING,&state_str);
 			if (state_str){
 				ms_message("Writing echo canceler state, %i bytes",(int)strlen(state_str));
-				lp_config_set_string(call->core->config,"sound","ec_state",state_str);
+				lp_config_write_relative_file(call->core->config, EC_STATE_STORE, state_str);
 			}
 		}
 		audio_stream_get_local_rtp_stats(call->audiostream,&call->log->local_stats);

coreapi/lpconfig.c

@@ -39,6 +39,12 @@
 #endif
 #endif /*_WIN32_WCE*/
 
+#ifdef WIN32
+#include <Shlwapi.h>
+#else
+#include <libgen.h>
+#endif
+
 
 
 #define lp_new0(type,n)	(type*)calloc(sizeof(type),n)
@@ -657,3 +663,55 @@ const char* lp_config_get_default_string(const LpConfig *lpconfig, const char *s
 
 	return lp_config_get_string(lpconfig, default_section, key, default_value);
 }
+
+static char *_lp_config_dirname(char *path) {
+#ifdef WIN32
+	char *dir = ms_strdup(path);
+	PathRemoveFileSpec(dir);
+	return dir;
+#else
+	char *tmp = ms_strdup(path);
+	char *dir = ms_strdup(dirname(tmp));
+	ms_free(tmp);
+	return dir;
+#endif
+}
+
+void lp_config_write_relative_file(const LpConfig *lpconfig, const char *filename, const char *data) {
+	if(strlen(data) > 0) {
+		char *dir = _lp_config_dirname(lpconfig->filename);
+		char *filepath = ms_strdup_printf("%s/%s", dir, filename);
+		FILE *file = fopen(filepath, "w");
+		if(file != NULL) {
+			fprintf(file, "%s", data);
+			fclose(file);
+		} else {
+			ms_error("Could not open %s for write", filepath);
+		}
+		ms_free(dir);
+		ms_free(filepath);
+	} else {
+		ms_warning("%s has not been created because there is no data to write", filename);
+	}
+}
+
+char *lp_config_read_relative_file(const LpConfig *lpconfig, const char *filename) {
+	char *dir = _lp_config_dirname(lpconfig->filename);
+	char *filepath = ms_strdup_printf("%s/%s", dir, filename);
+	char *result = NULL;
+	if(access(filepath, F_OK) == 0) {
+		FILE *file = fopen(filepath, "r");
+		if(file != NULL) {
+			result = ms_new0(char, MAX_LEN);
+			fgets(result, MAX_LEN, file);
+			fclose(file);
+		} else {
+			ms_error("Could not open %s for read", filepath);
+		}
+	} else {
+		ms_message("%s does not exist", filepath);
+	}
+	ms_free(dir);
+	ms_free(filepath);
+	return result;
+}

coreapi/lpconfig.h

@@ -272,6 +272,22 @@ LINPHONE_PUBLIC LpConfig *lp_config_ref(LpConfig *lpconfig);
 **/
 LINPHONE_PUBLIC void lp_config_unref(LpConfig *lpconfig);
 
+/**
+ * @brief Write a string in a file placed relatively with the Linphone configuration file.
+ * @param lpconfig LpConfig instance used as a reference
+ * @param filename Name of the file where to write data. The name is relative to the place of the config file
+ * @param data String to write
+ */
+LINPHONE_PUBLIC void lp_config_write_relative_file(const LpConfig *lpconfig, const char *filename, const char *data);
+
+/**
+ * @brief Read a string from a file placed relatively with the Linphone configuration file
+ * @param lpconfig LpConfig instance used as a reference
+ * @param filename Name of the file where data will be read from. The name is relative to the place of the config file
+ * @return The read string
+ */
+LINPHONE_PUBLIC char *lp_config_read_relative_file(const LpConfig *lpconfig, const char *filename);
+
 #ifdef __cplusplus
 }
 #endif