Added regexp-re2 library to external.
Change-Id: I54e60045f0fee91b64e4d7291e5bb6c6cffb4562
diff --git a/util/strutil.cc b/util/strutil.cc
new file mode 100644
index 0000000..6ab79b3
--- /dev/null
+++ b/util/strutil.cc
@@ -0,0 +1,97 @@
+// Copyright 1999-2005 The RE2 Authors. All Rights Reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "util/util.h"
+#include "re2/stringpiece.h"
+
+namespace re2 {
+
+// ----------------------------------------------------------------------
+// CEscapeString()
+// Copies 'src' to 'dest', escaping dangerous characters using
+// C-style escape sequences. 'src' and 'dest' should not overlap.
+// Returns the number of bytes written to 'dest' (not including the \0)
+// or -1 if there was insufficient space.
+// ----------------------------------------------------------------------
+int CEscapeString(const char* src, int src_len, char* dest,
+ int dest_len) {
+ const char* src_end = src + src_len;
+ int used = 0;
+
+ for (; src < src_end; src++) {
+ if (dest_len - used < 2) // Need space for two letter escape
+ return -1;
+
+ unsigned char c = *src;
+ switch (c) {
+ case '\n': dest[used++] = '\\'; dest[used++] = 'n'; break;
+ case '\r': dest[used++] = '\\'; dest[used++] = 'r'; break;
+ case '\t': dest[used++] = '\\'; dest[used++] = 't'; break;
+ case '\"': dest[used++] = '\\'; dest[used++] = '\"'; break;
+ case '\'': dest[used++] = '\\'; dest[used++] = '\''; break;
+ case '\\': dest[used++] = '\\'; dest[used++] = '\\'; break;
+ default:
+ // Note that if we emit \xNN and the src character after that is a hex
+ // digit then that digit must be escaped too to prevent it being
+ // interpreted as part of the character code by C.
+ if (c < ' ' || c > '~') {
+ if (dest_len - used < 4) // need space for 4 letter escape
+ return -1;
+ sprintf(dest + used, "\\%03o", c);
+ used += 4;
+ } else {
+ dest[used++] = c; break;
+ }
+ }
+ }
+
+ if (dest_len - used < 1) // make sure that there is room for \0
+ return -1;
+
+ dest[used] = '\0'; // doesn't count towards return value though
+ return used;
+}
+
+
+// ----------------------------------------------------------------------
+// CEscape()
+// Copies 'src' to result, escaping dangerous characters using
+// C-style escape sequences. 'src' and 'dest' should not overlap.
+// ----------------------------------------------------------------------
+string CEscape(const StringPiece& src) {
+ const int dest_length = src.size() * 4 + 1; // Maximum possible expansion
+ char* dest = new char[dest_length];
+ const int len = CEscapeString(src.data(), src.size(),
+ dest, dest_length);
+ string s = string(dest, len);
+ delete[] dest;
+ return s;
+}
+
+string PrefixSuccessor(const StringPiece& prefix) {
+ // We can increment the last character in the string and be done
+ // unless that character is 255, in which case we have to erase the
+ // last character and increment the previous character, unless that
+ // is 255, etc. If the string is empty or consists entirely of
+ // 255's, we just return the empty string.
+ bool done = false;
+ string limit(prefix.data(), prefix.size());
+ int index = limit.length() - 1;
+ while (!done && index >= 0) {
+ if ((limit[index]&255) == 255) {
+ limit.erase(index);
+ index--;
+ } else {
+ limit[index]++;
+ done = true;
+ }
+ }
+ if (!done) {
+ return "";
+ } else {
+ return limit;
+ }
+}
+
+} // namespace re2