Add the StringPiece class.
Change-Id: I4e8c303261f79553cfe4853d5c7e1adf851496fc
diff --git a/src/stringpiece.cc b/src/stringpiece.cc
new file mode 100644
index 0000000..098c6ef
--- /dev/null
+++ b/src/stringpiece.cc
@@ -0,0 +1,112 @@
+// Copyright 2010 Google
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <iostream>
+#include <utility>
+#include "src/stringpiece.h"
+
+using art::StringPiece;
+
+std::ostream& operator<<(std::ostream& o, const StringPiece& piece) {
+ o.write(piece.data(), piece.size());
+ return o;
+}
+
+bool operator==(const StringPiece& x, const StringPiece& y) {
+ int len = x.size();
+ if (len != y.size()) {
+ return false;
+ }
+ const char* p = x.data();
+ const char* p2 = y.data();
+ // Test last byte in case strings share large common prefix
+ if ((len > 0) && (p[len-1] != p2[len-1])) return false;
+ const char* p_limit = p + len;
+ for (; p < p_limit; p++, p2++) {
+ if (*p != *p2)
+ return false;
+ }
+ return true;
+}
+
+bool operator<(const art::StringPiece& x, const art::StringPiece& y) {
+ const int r = memcmp(x.data(), y.data(),
+ std::min(x.size(), y.size()));
+ return ((r < 0) || ((r == 0) && (x.size() < y.size())));
+}
+
+void StringPiece::CopyToString(std::string* target) const {
+ target->assign(ptr_, length_);
+}
+
+int StringPiece::copy(char* buf, size_type n, size_type pos) const {
+ int ret = std::min(length_ - pos, n);
+ memcpy(buf, ptr_ + pos, ret);
+ return ret;
+}
+
+int StringPiece::find(const StringPiece& s, size_type pos) const {
+ if (length_ < 0 || pos > static_cast<size_type>(length_))
+ return npos;
+
+ const char* result = std::search(ptr_ + pos, ptr_ + length_,
+ s.ptr_, s.ptr_ + s.length_);
+ const size_type xpos = result - ptr_;
+ return xpos + s.length_ <= static_cast<size_type>(length_) ? xpos : npos;
+}
+
+int StringPiece::compare(const StringPiece& x) const {
+ int r = memcmp(ptr_, x.ptr_, std::min(length_, x.length_));
+ if (r == 0) {
+ if (length_ < x.length_) r = -1;
+ else if (length_ > x.length_) r = +1;
+ }
+ return r;
+}
+
+int StringPiece::find(char c, size_type pos) const {
+ if (length_ <= 0 || pos >= static_cast<size_type>(length_)) {
+ return npos;
+ }
+ const char* result = std::find(ptr_ + pos, ptr_ + length_, c);
+ return result != ptr_ + length_ ? result - ptr_ : npos;
+}
+
+int StringPiece::rfind(const StringPiece& s, size_type pos) const {
+ if (length_ < s.length_) return npos;
+ const size_t ulen = length_;
+ if (s.length_ == 0) return std::min(ulen, pos);
+
+ const char* last = ptr_ + std::min(ulen - s.length_, pos) + s.length_;
+ const char* result = std::find_end(ptr_, last, s.ptr_, s.ptr_ + s.length_);
+ return result != last ? result - ptr_ : npos;
+}
+
+int StringPiece::rfind(char c, size_type pos) const {
+ if (length_ <= 0) return npos;
+ for (int i = std::min(pos, static_cast<size_type>(length_ - 1));
+ i >= 0; --i) {
+ if (ptr_[i] == c) {
+ return i;
+ }
+ }
+ return npos;
+}
+
+StringPiece StringPiece::substr(size_type pos, size_type n) const {
+ if (pos > static_cast<size_type>(length_)) pos = length_;
+ if (n > length_ - pos) n = length_ - pos;
+ return StringPiece(ptr_ + pos, n);
+}
+
+const StringPiece::size_type StringPiece::npos = size_type(-1);