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-rw-r--r--gfx/ots/include/ots-memory-stream.h109
1 files changed, 109 insertions, 0 deletions
diff --git a/gfx/ots/include/ots-memory-stream.h b/gfx/ots/include/ots-memory-stream.h
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+++ b/gfx/ots/include/ots-memory-stream.h
@@ -0,0 +1,109 @@
+// Copyright (c) 2009-2017 The OTS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef OTS_MEMORY_STREAM_H_
+#define OTS_MEMORY_STREAM_H_
+
+#include <cstring>
+#include <limits>
+
+#include "opentype-sanitiser.h"
+
+namespace ots {
+
+class MemoryStream : public OTSStream {
+ public:
+ MemoryStream(void *ptr, size_t length)
+ : ptr_(ptr), length_(length), off_(0) {
+ }
+
+ size_t size() override { return length_; }
+
+ bool WriteRaw(const void *data, size_t length) override {
+ if ((off_ + length > length_) ||
+ (length > std::numeric_limits<size_t>::max() - off_)) {
+ return false;
+ }
+ std::memcpy(static_cast<char*>(ptr_) + off_, data, length);
+ off_ += length;
+ return true;
+ }
+
+ bool Seek(off_t position) override {
+ if (position < 0) return false;
+ if (static_cast<size_t>(position) > length_) return false;
+ off_ = position;
+ return true;
+ }
+
+ off_t Tell() const override {
+ return off_;
+ }
+
+ private:
+ void* const ptr_;
+ size_t length_;
+ off_t off_;
+};
+
+class ExpandingMemoryStream : public OTSStream {
+ public:
+ ExpandingMemoryStream(size_t initial, size_t limit)
+ : length_(initial), limit_(limit), off_(0) {
+ ptr_ = new uint8_t[length_];
+ }
+
+ ~ExpandingMemoryStream() {
+ delete[] static_cast<uint8_t*>(ptr_);
+ }
+
+ void* get() const {
+ return ptr_;
+ }
+
+ size_t size() override { return limit_; }
+
+ bool WriteRaw(const void *data, size_t length) override {
+ if ((off_ + length > length_) ||
+ (length > std::numeric_limits<size_t>::max() - off_)) {
+ if (length_ == limit_)
+ return false;
+ size_t new_length = (length_ + 1) * 2;
+ if (new_length < length_)
+ return false;
+ if (new_length > limit_)
+ new_length = limit_;
+ uint8_t* new_buf = new uint8_t[new_length];
+ std::memcpy(new_buf, ptr_, length_);
+ length_ = new_length;
+ delete[] static_cast<uint8_t*>(ptr_);
+ ptr_ = new_buf;
+ return WriteRaw(data, length);
+ }
+ std::memcpy(static_cast<char*>(ptr_) + off_, data, length);
+ off_ += length;
+ return true;
+ }
+
+ bool Seek(off_t position) override {
+ if (position < 0) return false;
+ if (static_cast<size_t>(position) > length_) return false;
+ off_ = position;
+ return true;
+ }
+
+ off_t Tell() const override {
+ return off_;
+ }
+
+ private:
+ void* ptr_;
+ size_t length_;
+ const size_t limit_;
+ off_t off_;
+};
+
+} // namespace ots
+
+#endif // OTS_MEMORY_STREAM_H_