issue #82 improve buffer management

vscode-debugger/src/protocol.c

@@ -4,6 +4,61 @@
 #include <stdbool.h>
 #include <stdio.h>
 #include <string.h>
+#include <stdlib.h>
+
+void membuff_init(membuff_t *mb, size_t initial_size) {
+  if (initial_size > 0) {
+    mb->buf = (char *)calloc(1, initial_size);
+    if (mb->buf == NULL) {
+      fprintf(stderr, "out of memory\n");
+      exit(1);
+    }
+  }
+  else
+    mb->buf = NULL;
+  mb->pos = 0;
+  mb->allocated_size = initial_size;
+}
+void membuff_rewindpos(membuff_t *mb) {
+  mb->pos = 0;
+}
+void membuff_resize(membuff_t *mb, size_t new_size) {
+  if (new_size <= mb->allocated_size)
+    return;
+  char *newmem = (char *)realloc(mb->buf, new_size);
+  if (newmem == NULL) {
+    fprintf(stderr, "out of memory\n");
+    exit(1);
+  }
+  mb->buf = newmem;
+  mb->allocated_size = new_size;
+}
+void membuff_free(membuff_t *mb) {
+  free(mb->buf);
+}
+void membuff_add_string(membuff_t *mb, const char *str) {
+  size_t len = strlen(str);
+  size_t required_size = mb->pos + len + 1; /* extra byte for NULL terminator */
+  membuff_resize(mb, required_size);
+  vscode_string_copy(&mb->buf[mb->pos], str, mb->allocated_size-mb->pos);
+  mb->pos += len;
+}
+void membuff_add_bool(membuff_t *mb, bool value) {
+  if (value)
+    membuff_add_string(mb, "true");
+  else
+    membuff_add_string(mb, "false");
+}
+void membuff_add_int(membuff_t *mb, int value) {
+  char temp[100];
+  snprintf(temp, sizeof temp, "%d", value);
+  membuff_add_string(mb, temp);
+}
+void membuff_add_longlong(membuff_t *mb, long long value) {
+  char temp[100];
+  snprintf(temp, sizeof temp, "%lld", value);
+  membuff_add_string(mb, temp);
+}
 
 /* Parse a VSCode JSON message type
  */

vscode-debugger/src/protocol.h

@@ -344,6 +344,22 @@ typedef struct {
 
 } ProtocolMessage;
 
+
+typedef struct {
+  char *buf;
+  size_t allocated_size;
+  size_t pos;
+} membuff_t;
+
+extern void membuff_init(membuff_t *mb, size_t initial_size);
+extern void membuff_rewindpos(membuff_t *mb);
+extern void membuff_resize(membuff_t *mb, size_t new_size);
+extern void membuff_free(membuff_t *mb);
+extern void membuff_add_string(membuff_t *mb, const char *str);
+extern void membuff_add_bool(membuff_t *mb, bool value);
+extern void membuff_add_int(membuff_t *mb, int value);
+extern void membuff_add_longlong(membuff_t *mb, long long value);
+
 extern int vscode_parse_message(char *buf, size_t len, ProtocolMessage *msg,
                                 FILE *log);
 extern void vscode_make_error_response(ProtocolMessage *req,

vscode-debugger/src/ravidebug.c

@@ -978,12 +978,21 @@ static void createargtable(lua_State *L, char **argv, int argc, int script) {
   lua_setglobal(L, "arg");
 }
 
+static inline bool is_bigendian() {
+  static const int i = 1;
+  return (*((char *)&i)) == 0;
+}
+
 /*
 * Entry point for the debugger
 * The debugger will use stdin/stdout to interact with VSCode
 * The protocol used is described in protocol.h.
 */
 int main(int argc, char **argv) {
+  if (is_bigendian()) {
+    fprintf(stderr, "Big endian architecture not supported\n");
+    exit(1);
+  }
 /* For debugging purposes we log the interaction */
 #ifdef _WIN32
   my_logger = fopen("/temp/out1.txt", "w");