upb_stringsrc: upb_bytesrc for strings.

stream/upb_strstream.c

@@ -0,0 +1,62 @@
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2010 Joshua Haberman.  See LICENSE for details.
+ */
+
+#include "upb_strstream.h"
+
+#include <stdlib.h>
+#include "upb_string.h"
+
+struct upb_stringsrc {
+  upb_bytesrc bytesrc;
+  upb_string *str;
+};
+
+void upb_stringsrc_reset(upb_stringsrc *s, upb_string *str) {
+  if (str != s->str) {
+    if (s->str) upb_string_unref(s->str);
+    s->str = upb_string_getref(str);
+  }
+  s->bytesrc.eof = false;
+}
+
+void upb_stringsrc_free(upb_stringsrc *s) {
+  if (s->str) upb_string_unref(s->str);
+  free(s);
+}
+
+static bool upb_stringsrc_get(upb_stringsrc *src, upb_string *str,
+                              upb_strlen_t minlen) {
+  // We ignore "minlen" since we always return the entire string.
+  (void)minlen;
+  upb_string_substr(str, src->str, 0, upb_string_len(src->str));
+  src->bytesrc.eof = true;
+  return true;
+}
+
+static bool upb_stringsrc_append(upb_stringsrc *src, upb_string *str,
+                                 upb_strlen_t len) {
+  // Unimplemented; since we return the string via "get" all in one go,
+  // this method probably isn't very useful.
+  (void)src;
+  (void)str;
+  (void)len;
+  return false;
+}
+
+static upb_bytesrc_vtable upb_stringsrc_vtbl = {
+  (upb_bytesrc_get_fptr)upb_stringsrc_get,
+  (upb_bytesrc_append_fptr)upb_stringsrc_append,
+};
+
+upb_stringsrc *upb_stringsrc_new() {
+  upb_stringsrc *s = malloc(sizeof(*s));
+  upb_bytesrc_init(&s->bytesrc, &upb_stringsrc_vtbl);
+  return s;
+}
+
+upb_bytesrc *upb_stringsrc_bytesrc(upb_stringsrc *s) {
+  return &s->bytesrc;
+}