Diff: M2XStreamClient/LocationParseFunctions.h

Revision:

3:78f223d34f36

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/M2XStreamClient/LocationParseFunctions.h	Tue Mar 05 02:34:44 2019 +0000
@@ -0,0 +1,100 @@
+#ifndef LocationParseFunctions_h
+#define LocationParseFunctions_h
+
+// Data structures and functions used to parse locations
+
+#define LOCATION_BUF_LEN 20
+
+typedef struct {
+  uint16_t state;
+  char name_str[LOCATION_BUF_LEN + 1];
+  double latitude;
+  double longitude;
+  double elevation;
+  char timestamp_str[LOCATION_BUF_LEN + 1];
+  int index;
+
+  location_read_callback callback;
+  void* context;
+} location_parsing_context_state;
+
+#define WAITING_NAME 0x1
+#define WAITING_LATITUDE 0x2
+#define WAITING_LONGITUDE 0x4
+#define WAITING_ELEVATION 0x8
+#define WAITING_TIMESTAMP 0x10
+
+#define GOT_NAME 0x20
+#define GOT_LATITUDE 0x40
+#define GOT_LONGITUDE 0x80
+#define GOT_ELEVATION 0x100
+#define GOT_TIMESTAMP 0x200
+
+#define GOT_LOCATION (GOT_NAME | GOT_LATITUDE | GOT_LONGITUDE | GOT_ELEVATION | GOT_TIMESTAMP)
+#define TEST_GOT_LOCATION(state_) (((state_) & GOT_LOCATION) == GOT_LOCATION)
+
+#define TEST_IS_NAME(state_) (((state_) & (WAITING_NAME | GOT_NAME)) == WAITING_NAME)
+#define TEST_IS_LATITUDE(state_) (((state_) & (WAITING_LATITUDE | GOT_LATITUDE)) \
+                                  == WAITING_LATITUDE)
+#define TEST_IS_LONGITUDE(state_) (((state_) & (WAITING_LONGITUDE | GOT_LONGITUDE)) \
+                                   == WAITING_LONGITUDE)
+#define TEST_IS_ELEVATION(state_) (((state_) & (WAITING_ELEVATION | GOT_ELEVATION)) \
+                                   == WAITING_ELEVATION)
+#define TEST_IS_TIMESTAMP(state_) (((state_) & (WAITING_TIMESTAMP | GOT_TIMESTAMP)) \
+                                   == WAITING_TIMESTAMP)
+
+static void on_location_key_found(jsonlite_callback_context* context,
+                                  jsonlite_token* token) {
+  location_parsing_context_state* state =
+      (location_parsing_context_state*) context->client_state;
+  if (strncmp((const char*) token->start, "waypoints", 9) == 0) {
+    // only parses those locations in waypoints, skip the outer one
+    state->state = 0;
+  } else if (strncmp((const char*) token->start, "name", 4) == 0) {
+    state->state |= WAITING_NAME;
+  } else if (strncmp((const char*) token->start, "latitude", 8) == 0) {
+    state->state |= WAITING_LATITUDE;
+  } else if (strncmp((const char*) token->start, "longitude", 9) == 0) {
+    state->state |= WAITING_LONGITUDE;
+  } else if (strncmp((const char*) token->start, "elevation", 9) == 0) {
+    state->state |= WAITING_ELEVATION;
+  } else if (strncmp((const char*) token->start, "timestamp", 9) == 0) {
+    state->state |= WAITING_TIMESTAMP;
+  }
+}
+
+static void on_location_string_found(jsonlite_callback_context* context,
+                                     jsonlite_token* token) {
+  location_parsing_context_state* state =
+      (location_parsing_context_state*) context->client_state;
+
+  if (TEST_IS_NAME(state->state)) {
+    strncpy(state->name_str, (const char*) token->start,
+            MIN(token->end - token->start, LOCATION_BUF_LEN));
+    state->name_str[MIN(token->end - token->start, LOCATION_BUF_LEN)] = '\0';
+    state->state |= GOT_NAME;
+  } else if (TEST_IS_LATITUDE(state->state)) {
+    state->latitude = atof((const char*) token->start);
+    state->state |= GOT_LATITUDE;
+  } else if (TEST_IS_LONGITUDE(state->state)) {
+    state->longitude = atof((const char*) token->start);
+    state->state |= GOT_LONGITUDE;
+  } else if (TEST_IS_ELEVATION(state->state)) {
+    state->elevation = atof((const char*) token->start);
+    state->state |= GOT_ELEVATION;
+  } else if (TEST_IS_TIMESTAMP(state->state)) {
+    strncpy(state->timestamp_str, (const char*) token->start,
+            MIN(token->end - token->start, LOCATION_BUF_LEN));
+    state->timestamp_str[MIN(token->end - token->start, LOCATION_BUF_LEN)] = '\0';
+    state->state |= GOT_TIMESTAMP;
+  }
+
+  if (TEST_GOT_LOCATION(state->state)) {
+    state->callback(state->name_str, state->latitude, state->longitude,
+                    state->elevation, state->timestamp_str, state->index++,
+                    state->context);
+    state->state = 0;
+  }
+}
+
+#endif  /* LocationParseFunctions_h */