From: Jeremy Tan <jeremy@jx.tan.fake>
Date: Thu, 12 Sep 2013 14:06:26 +0000 (+0800)
Subject: Add request parsing helper, add TIMEVAL_* macros, move timestamps to identify module
X-Git-Url: https://git.ucc.asn.au/?a=commitdiff_plain;h=a0c96fa8feb1938db84d95b14c320e6c7511c282;p=matches%2FMCTX3420.git

Add request parsing helper, add TIMEVAL_* macros, move timestamps to identify module
---

diff --git a/server/common.h b/server/common.h
index 1275032..c2edd3d 100644
--- a/server/common.h
+++ b/server/common.h
@@ -28,4 +28,9 @@
 #include "fastcgi.h"
 #include "thread.h"
 
+/**Converts a timeval to a double**/
+#define TIMEVAL_TO_DOUBLE(tv) ((tv).tv_sec + 1e-6 * ((tv).tv_usec))
+/**Takes the tv1-tv2 between two timevals and returns the result as a double*/
+#define TIMEVAL_DIFF(tv1, tv2) ((tv1).tv_sec - (tv2).tv_sec + 1e-6 * ((tv1).tv_usec - (tv2).tv_usec))
+
 #endif //_COMMON_H
diff --git a/server/fastcgi.c b/server/fastcgi.c
index e41e375..8c6355a 100644
--- a/server/fastcgi.c
+++ b/server/fastcgi.c
@@ -8,6 +8,7 @@
 
 #include <fcgi_stdio.h>
 #include <openssl/sha.h>
+#include <stdarg.h>
 
 #include "common.h"
 #include "sensor.h"
@@ -37,23 +38,38 @@ struct FCGIContext {
  * @param params User specified paramters: [actuators, sensors]
  */ 
 static void IdentifyHandler(FCGIContext *context, char *params) {
-	bool identSensors = false, identActuators = false;
-	const char *key, *value;
+	bool ident_sensors = false, ident_actuators = false;
+	//const char *key, *value;
+	struct timeval now;
 	int i;
 
-	while ((params = FCGI_KeyPair(params, &key, &value))) {
+	FCGIValue values[2] = {{"sensors", &ident_sensors, FCGI_BOOL_T},
+					 {"actuators", &ident_actuators, FCGI_BOOL_T}};
+
+	if (!FCGI_ParseRequest(context, params, values, 2))
+		return;
+
+	/*while ((params = FCGI_KeyPair(params, &key, &value))) {
 		if (!strcmp(key, "sensors")) {
-			identSensors = !identSensors;
+			ident_sensors = !ident_sensors;
 		} else if (!strcmp(key, "actuators")) {
-			identActuators = !identActuators;
+			ident_actuators = !ident_actuators;
 		}
-	}
+	}*/
 
 	FCGI_BeginJSON(context, STATUS_OK);
 	FCGI_JSONPair("description", "MCTX3420 Server API (2013)");
 	FCGI_JSONPair("build_date", __DATE__ " " __TIME__);
 	FCGI_JSONLong("api_version", API_VERSION);
-	if (identSensors) {
+
+	//Time and running statistics
+	gettimeofday(&now, NULL);
+	FCGI_JSONDouble("start_time", TIMEVAL_TO_DOUBLE(g_options.start_time));
+	FCGI_JSONDouble("current_time", TIMEVAL_TO_DOUBLE(now));
+	FCGI_JSONDouble("running_time", TIMEVAL_DIFF(now, g_options.start_time));
+
+	//Sensor and actuator information
+	if (ident_sensors) {
 		FCGI_JSONKey("sensors");
 		FCGI_JSONValue("{\n\t\t");
 		for (i = 0; i < NUMSENSORS; i++) {
@@ -64,7 +80,7 @@ static void IdentifyHandler(FCGIContext *context, char *params) {
 		}
 		FCGI_JSONValue("\n\t}");
 	}
-	if (identActuators) {
+	if (ident_actuators) {
 		FCGI_JSONKey("actuators");
 		FCGI_JSONValue("{\n\t\t");
 		for (i = 0; i < NUMACTUATORS; i++) {
@@ -189,6 +205,87 @@ char *FCGI_KeyPair(char *in, const char **key, const char **value)
 	return ptr;
 }
 
+/**
+ * Aids in parsing request parameters. Expected keys along with their type
+ * and whether or not they're required are provided. This function will then
+ * parse the parameter string to find these keys.
+ * @param context The context to work in
+ * @param params The parameter string to be parsed
+ * @param values An array of FCGIValue's that specify expected keys
+ * @param count The number of elements in 'values'.
+ * @return true If the parameter string was parsed successfully, false otherwise.
+ *         Modes of failure include: Invalid a parsing error on the value,
+ *                                   an unknown key is specified,
+ *                                   a key/value pair is specified more than once, or
+ *                                   not all required keys were present.
+ *         If this function returns false, it is guaranteed that FCGI_RejectJSON
+ *         has already been called with the appropriate description message.
+ */
+bool FCGI_ParseRequest(FCGIContext *context, char *params, FCGIValue values[], size_t count)
+{
+	const char *key, *value;
+	char buf[BUFSIZ], *ptr;
+	size_t i;
+	
+	while ((params = FCGI_KeyPair(params, &key, &value))) {
+		for (i = 0; i < count; i++) {
+			if (!strcmp(key, values[i].key)) {
+				FCGIValue *val = &values[i];
+
+				if (FCGI_RECEIVED(val->flags)) {
+					snprintf(buf, BUFSIZ, "Value already specified for '%s'.", key);
+					FCGI_RejectJSON(context, buf);
+					return false;
+				}
+				val->flags |= FCGI_PARAM_RECEIVED;
+
+				switch(FCGI_TYPE(val->flags)) {
+					case FCGI_BOOL_T:
+						*((bool*) val->value) = true;
+						break;
+					case FCGI_LONG_T:
+						*((long*) val->value) = strtol(value, &ptr, 10);
+						if (!*value || *ptr) {
+							snprintf(buf, BUFSIZ, "Expected int for '%s' but got '%s'", key, value);
+							FCGI_RejectJSON(context, FCGI_EscapeJSON(buf));
+							return false;
+						}
+						break;
+					case FCGI_DOUBLE_T:
+						*((double*) val->value) = strtod(value, &ptr);
+						if (!*value || *ptr) {
+							snprintf(buf, BUFSIZ, "Expected float for '%s' but got '%s'", key, value);
+							FCGI_RejectJSON(context, FCGI_EscapeJSON(buf));
+							return false;
+						}
+						break;
+					case FCGI_STRING_T:
+						*((const char**) val->value) = value;
+						break;
+					default:
+						Fatal("Invalid type %d given", FCGI_TYPE(val->flags));
+				}
+				break; //No need to search any more
+			}
+		} //End for loop
+		if (i == count) {
+			snprintf(buf, BUFSIZ, "Unknown key '%s' specified", key);
+			FCGI_RejectJSON(context, FCGI_EscapeJSON(buf));
+			return false;
+		}
+	}
+
+	//Check that required parameters are received
+	for (i = 0; i < count; i++) {
+		if (FCGI_IS_REQUIRED(values[i].flags) && !FCGI_RECEIVED(values[i].flags)) {
+			snprintf(buf, BUFSIZ, "Key '%s' required, but was not given.", values[i].key);
+			FCGI_RejectJSON(context, buf);
+			return false;
+		}
+	}
+	return true;
+}
+
 /**
  * Begins a response to the client in JSON format.
  * @param context The context to work in.
@@ -200,20 +297,11 @@ void FCGI_BeginJSON(FCGIContext *context, StatusCodes status_code)
 	printf("{\r\n");
 	printf("\t\"module\" : \"%s\"", context->current_module);
 	FCGI_JSONLong("status", status_code);
-
-	// Jeremy: Should we include a timestamp in the JSON; something like this?
-	double start_time = g_options.start_time.tv_sec + 1e-6*(g_options.start_time.tv_usec);
-	struct timeval now;
-	gettimeofday(&now, NULL);
-	double current_time = now.tv_sec + 1e-6*(now.tv_usec);
-	FCGI_JSONDouble("start_time", start_time);
-	FCGI_JSONDouble("current_time", current_time);
-	FCGI_JSONDouble("running_time", current_time - start_time);
 }
 
 /**
  * Adds a key/value pair to a JSON response. The response must have already
- * been initiated by FCGI_BeginJSON. Note that characters are not escaped.
+ * been initiated by FCGI_BeginJSON. Special characters are not escaped.
  * @param key The key of the JSON entry
  * @param value The value associated with the key.
  */
@@ -270,6 +358,36 @@ void FCGI_EndJSON()
 	printf("\r\n}\r\n");
 }
 
+/**
+ * Escapes a string so it can be used as a JSON string value.
+ * Does not support unicode specifiers in the form of \uXXXX.
+ * @param buf The string to be escaped
+ * @return The escaped string (return value == buf)
+ */
+char *FCGI_EscapeJSON(char *buf)
+{
+	int length, i;
+	length = strlen(buf);
+	
+	//Escape special characters. Must count down to escape properly
+	for (i = length - 1; i >= 0; i--) {
+		if (buf[i] < 0x20) { //Control characters
+			buf[i] = ' ';
+		} else if (buf[i] == '"') {
+			if (i-1 >= 0 && buf[i-1] == '\\') 
+				i--;
+			else
+				buf[i] = '\'';
+		} else if (buf[i] == '\\') {
+			if (i-1 >= 0 && buf[i-1] == '\'')
+				i--;
+			else
+				buf[i] = ' ';
+		}
+	}
+	return buf;
+}
+
 /**
  * To be used when the input parameters are rejected. The return data
  * will also have debugging information provided.
@@ -355,7 +473,7 @@ void * FCGI_RequestLoop (void *data)
 		} else if (!strcmp("control", module)) {
 			module_handler = Control_Handler;
 		} else if (!strcmp("sensors", module)) {
-			module_handler = Sensor_Handler2;
+			module_handler = Sensor_Handler;
 		}
 
 		context.current_module = module;
diff --git a/server/fastcgi.h b/server/fastcgi.h
index 9a37a6f..965cf5c 100644
--- a/server/fastcgi.h
+++ b/server/fastcgi.h
@@ -20,6 +20,23 @@ typedef enum StatusCodes {
 	STATUS_OUTOFRANGE = -3
 } StatusCodes;
 
+#define FCGI_PARAM_REQUIRED (1 << 0)
+#define FCGI_PARAM_RECEIVED (1 << 1)
+#define FCGI_BOOL_T (1 << 2)
+#define FCGI_LONG_T (1 << 3)
+#define FCGI_DOUBLE_T (1 << 4)
+#define FCGI_STRING_T (1 << 5)
+#define FCGI_REQUIRED(x) ((x) | FCGI_PARAM_REQUIRED)
+#define FCGI_IS_REQUIRED(x) ((x) & FCGI_PARAM_REQUIRED)
+#define FCGI_RECEIVED(x) ((x) & FCGI_PARAM_RECEIVED)
+#define FCGI_TYPE(x) ((x) & ~(FCGI_PARAM_REQUIRED | FCGI_PARAM_RECEIVED))
+
+typedef struct FCGIValue {
+	const char *key;
+	void *value;
+	unsigned flags;
+} FCGIValue;
+
 typedef struct FCGIContext FCGIContext;
 typedef void (*ModuleHandler) (FCGIContext *context, char *params);
 
@@ -27,6 +44,7 @@ extern void FCGI_BeginControl(FCGIContext *context, bool force);
 extern void FCGI_EndControl(FCGIContext *context);
 extern bool FCGI_HasControl(FCGIContext *context, const char *key);
 extern char *FCGI_KeyPair(char *in, const char **key, const char **value);
+extern bool FCGI_ParseRequest(FCGIContext *context, char *params, FCGIValue values[], size_t count);
 extern void FCGI_BeginJSON(FCGIContext *context, StatusCodes status_code);
 extern void FCGI_JSONPair(const char *key, const char *value);
 extern void FCGI_JSONLong(const char *key, long value);
@@ -35,6 +53,7 @@ extern void FCGI_JSONBool(const char *key, bool value);
 extern void FCGI_JSONKey(const char *key);
 extern void FCGI_PrintRaw(const char *format, ...);
 extern void FCGI_EndJSON();
+extern char *FCGI_EscapeJSON(char *buf);
 extern void FCGI_RejectJSONEx(FCGIContext *context, StatusCodes status, const char *description);
 extern void *FCGI_RequestLoop (void *data);
 
diff --git a/server/sensor.c b/server/sensor.c
index 9055409..f2c73c5 100644
--- a/server/sensor.c
+++ b/server/sensor.c
@@ -35,7 +35,7 @@ DataPoint * GetData(SensorId sensor_id, DataPoint * d)
 	
 	struct timeval t;
 	gettimeofday(&t, NULL);
-	d->time_stamp = (t.tv_sec - g_options.start_time.tv_sec) + 1e-6*(t.tv_usec - g_options.start_time.tv_usec);
+	d->time_stamp = TIMEVAL_DIFF(t, g_options.start_time);
 
 	// Make time relative
 	//d->time_stamp.tv_sec -= g_options.start_time.tv_sec;
@@ -385,13 +385,23 @@ void Sensor_Handler(FCGIContext *context, char * params)
 
 	double start_time = -1;
 	double end_time = -1;
-	double current_time = (now.tv_sec - g_options.start_time.tv_sec) + 1e-6*(now.tv_usec - g_options.start_time.tv_usec);
+	double current_time = TIMEVAL_DIFF(now, g_options.start_time)
 	bool seek_time = false;
 	bool points_specified = false;
 	int query_size = SENSOR_QUERYBUFSIZ;
 	int start_index = -1;
 	int end_index = -1;
 
+	/* //Possible use case?
+	FCGIValue values[5] = {
+		{"id", &id, FCGI_REQUIRED(FCGI_INT_T)},
+		{"format", &format, FCGI_STRING_T},
+		{"points", &points, FCGI_STRING_T},
+		{"start_time", &start_time, FCGI_DOUBLE_T},
+		{"end_time", &end_time, FCGI_DOUBLE_T}
+	};
+	if (!FCGI_ParseRequest(context, params, values, 5))
+		return;*/
 
 	while ((params = FCGI_KeyPair(params, &key, &value)) != NULL)
 	{