From 462b26c1cc041a8fa26deb62cf12f1f351a5b2f6 Mon Sep 17 00:00:00 2001
From: Joshua Haberman <joshua@reverberate.org>
Date: Wed, 8 Jul 2009 12:06:47 -0700
Subject: Directory restructuring.

---
 src/upb_string.h | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 82 insertions(+)
 create mode 100644 src/upb_string.h

(limited to 'src/upb_string.h')

diff --git a/src/upb_string.h b/src/upb_string.h
new file mode 100644
index 0000000..7a05811
--- /dev/null
+++ b/src/upb_string.h
@@ -0,0 +1,82 @@
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2009 Joshua Haberman.  See LICENSE for details.
+
+ * Defines a delimited (as opposed to null-terminated) string type and some
+ * library functions for manipulating them.
+ *
+ * There are two primary reasons upb uses delimited strings.  One is that they
+ * can be more efficient for some operations because they do not have to scan
+ * the string to find its length.  For example, streql can start by just
+ * comparing the lengths (very efficient) and scan the strings themselves only
+ * if the lengths are equal.
+ *
+ * More importantly, using delimited strings makes it possible for strings to
+ * reference substrings of other strings.  For example, if I am parsing a
+ * protobuf I can create a string that references the original protobuf's
+ * string data.  With NULL-termination I would be forced to write a NULL
+ * into the middle of the protobuf's data, which is less than ideal and in
+ * some cases not practical or possible.
+ */
+
+#ifndef UPB_STRING_H_
+#define UPB_STRING_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include "upb.h"
+
+struct upb_string {
+  /* We expect the data to be 8-bit clean (uint8_t), but char* is such an
+   * ingrained convention that we follow it. */
+  char *ptr;
+  uint32_t byte_len;
+};
+
+INLINE bool upb_streql(struct upb_string *s1, struct upb_string *s2) {
+  return s1->byte_len == s2->byte_len &&
+         memcmp(s1->ptr, s2->ptr, s1->byte_len) == 0;
+}
+
+INLINE void upb_strcpy(struct upb_string *dest, struct upb_string *src) {
+  memcpy(dest->ptr, src->ptr, dest->byte_len);
+  dest->byte_len = src->byte_len;
+}
+
+INLINE struct upb_string upb_strdup(struct upb_string s) {
+  struct upb_string copy;
+  copy.ptr = (char*)malloc(s.byte_len);
+  copy.byte_len = s.byte_len;
+  memcpy(copy.ptr, s.ptr, s.byte_len);
+  return copy;
+}
+
+INLINE void upb_strfree(struct upb_string s) {
+  free(s.ptr);
+}
+
+/* Reads an entire file into a newly-allocated string. */
+bool upb_strreadfile(const char *filename, struct upb_string *data);
+
+/* Allows defining upb_strings as literals, ie:
+ *   struct upb_string str = UPB_STRLIT("Hello, World!\n");
+ * Doesn't work with C++ due to lack of struct initializer syntax.
+ */
+#define UPB_STRLIT(strlit) {.ptr=strlit, .byte_len=sizeof(strlit)-1}
+
+/* Allows using upb_strings in printf, ie:
+ *   struct upb_string str = UPB_STRLIT("Hello, World!\n");
+ *   printf("String is: " UPB_STRFMT, UPB_STRARG(str)); */
+#define UPB_STRARG(str) (str).byte_len, (str).ptr
+#define UPB_STRFMT "%.*s"
+
+#ifdef __cplusplus
+}  /* extern "C" */
+#endif
+
+#endif  /* UPB_H_ */
-- 
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