Import of the watch repository from Pebble

third_party/nanopb/tests/msgid/decode_msgid.c

@@ -0,0 +1,105 @@
+/* Decode a message using msgid prefix to identify message type */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <pb_decode.h>
+#include "msgid_example.pb.h"
+#include "test_helpers.h"
+
+/* This function reads the prefix written by sending side. */
+bool read_prefix(pb_istream_t *stream, int *msgid)
+{
+    uint8_t prefix = 0;
+
+    if (!pb_read(stream, &prefix, 1))
+        return false;
+
+    *msgid = prefix;
+    return true;
+}
+
+/* Main function will call one of these functions based on the prefix */
+
+bool handle_MyMessage1(pb_istream_t *stream)
+{
+    MyMessage1 msg = MyMessage1_init_default;
+
+    if (!pb_decode(stream, MyMessage1_fields, &msg))
+        return false;
+
+    printf("Got MyMessage1: intvalue = %d\n", (int)msg.intvalue);
+    return true;
+}
+
+bool handle_MyMessage2(pb_istream_t *stream)
+{
+    MyMessage2 msg = MyMessage2_init_default;
+
+    if (!pb_decode(stream, MyMessage2_fields, &msg))
+        return false;
+
+    printf("Got MyMessage2: intvalue = %d, strvalue = %s\n",
+           (int)msg.intvalue, msg.strvalue);
+    return true;
+}
+
+bool handle_MyMessage3(pb_istream_t *stream)
+{
+    MyMessage3 msg = MyMessage3_init_default;
+
+    if (!pb_decode(stream, MyMessage3_fields, &msg))
+        return false;
+
+    printf("Got MyMessage3: boolvalue = %d\n", (int)msg.boolvalue);
+    return true;
+}
+
+int main(int argc, char **argv)
+{
+    uint8_t buffer[128];
+    pb_istream_t stream;
+    size_t count;
+    bool status = false;
+    int prefix;
+
+    /* Read the data into buffer */
+    SET_BINARY_MODE(stdin);
+    count = fread(buffer, 1, sizeof(buffer), stdin);
+
+    if (!feof(stdin))
+    {
+        printf("Message does not fit in buffer\n");
+        return 1;
+    }
+
+    stream = pb_istream_from_buffer(buffer, count);
+
+    if (!read_prefix(&stream, &prefix))
+    {
+        printf("Failed to read prefix: %s\n", PB_GET_ERROR(&stream));
+        return 1;
+    }
+
+    /* Call message handler based on prefix.
+     * We could write the switch cases manually, comparing against
+     * the MyMessageX_msgid defines. However, this uses the automatically
+     * generated X-macro construct to make the switch case.
+     */
+
+    switch (prefix)
+    {
+        #define PB_MSG(id,len,name) case id: status = handle_ ## name(&stream); break;
+        MSGID_EXAMPLE_MESSAGES
+        #undef PB_MSG
+
+        default: printf("Unknown prefix: %d\n", prefix); return 1;
+    }
+
+    if (!status)
+    {
+        printf("Parsing failed: %s\n", PB_GET_ERROR(&stream));
+        return 1;
+    } else {
+        return 0;
+    }
+}