Config parser

1 files changed, 138 insertions, 0 deletions

diff --git a/config.c b/config.c
new file mode 100644
index 0000000..de6767d
--- /dev/null
+++ b/config.c
@@ -0,0 +1,138 @@
+#include <string.h>
+#include <ctype.h>
+#include "midimonster.h"
+#include "config.h"
+#include "backend.h"
+
+enum {
+	none,
+	backend_cfg,
+	instance_cfg,
+	map
+} parser_state = none;
+
+backend* current_backend = NULL;
+instance* current_instance = NULL;
+
+static char* config_trim_line(char* in){
+	ssize_t u;
+	//trim front
+	for(; *in && !isgraph(*in); in++){
+	}
+
+	//trim back
+	for(u = strlen(in); u >= 0 && !isgraph(in[u]); u--){
+		in[u] = 0;
+	}
+
+	return in;
+}
+
+int config_read(char* cfg_file){
+	int rv = 1;
+	size_t line_alloc = 0;
+	ssize_t status;
+	char* line_raw = NULL, *line, *separator;
+	FILE* source = fopen(cfg_file, "r");
+	if(!source){
+		fprintf(stderr, "Failed to open configuration file for reading\n");
+		return 1;
+	}
+
+	for(status = getline(&line_raw, &line_alloc, source); status >= 0; status = getline(&line_raw, &line_alloc, source)){
+		line = config_trim_line(line_raw);
+		if(*line == ';' || strlen(line) == 0){
+			//skip comments
+			continue;
+		}
+		if(*line == '[' && line[strlen(line) - 1] == ']'){
+			if(!strncmp(line, "[backend ", 9)){
+				//backend configuration
+				parser_state = backend_cfg;
+				line[strlen(line) - 1] = 0;
+				current_backend = backend_match(line + 9);
+
+				if(!current_backend){
+					fprintf(stderr, "Cannot configure unknown backend %s\n", line + 9);
+					goto bail;
+				}
+			}
+			else if(!strcmp(line, "[map]")){
+				//mapping configuration
+				parser_state = map;
+			}
+			else{
+				//backend instance configuration
+				parser_state = instance_cfg;
+				
+				//trim braces
+				line[strlen(line) - 1] = 0;
+				line++;
+
+				//find separating space and terminate
+				for(separator = line; *separator && *separator != ' '; separator++){
+				}
+				if(!*separator){
+					fprintf(stderr, "No instance name specified for backend %s\n", line);
+					goto bail;
+				}
+				*separator = 0;
+				separator++;
+
+				current_backend = backend_match(line);
+				if(!current_backend){
+					fprintf(stderr, "No such backend %s\n", line);
+					goto bail;
+				}
+
+				current_instance = current_backend->create();
+				if(!current_instance){
+					fprintf(stderr, "Failed to instantiate backend %s\n", line);
+					goto bail;
+				}
+
+				current_instance->name = strdup(separator);
+				current_instance->backend = current_backend;
+				fprintf(stderr, "Created %s instance %s\n", line, separator);
+			}
+		}
+		else{
+			//pass to parser
+			//find separator
+			for(separator = line; *separator && *separator != '='; separator++){
+			}
+
+			if(!*separator){
+				fprintf(stderr, "No assignment: %s\n", line);
+				goto bail;
+			}
+
+			*separator = 0;
+			separator++;
+
+			if(parser_state == backend_cfg && current_backend->conf(config_trim_line(line), config_trim_line(separator))){
+				fprintf(stderr, "Failed to configure backend %s\n", current_backend->name);
+				goto bail;
+			}
+			else if(parser_state == instance_cfg && current_backend->conf_instance(current_instance, config_trim_line(line), config_trim_line(separator))){
+				fprintf(stderr, "Failed to configure instance %s\n", current_instance->name);
+				goto bail;
+			}
+			else if(parser_state == map){
+				//TODO map two channels
+			}
+		}
+	}
+
+	rv = 0;
+bail:
+	fclose(source);
+	free(line_raw);
+	return rv;
+}
+
+void mm_instance_free(instance* inst){
+	free(inst->name);
+	inst->name = NULL;
+	inst->backend = NULL;
+}