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// Copyright 2015 The Chromium 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 PDF_PDFIUM_PDFIUM_API_STRING_BUFFER_ADAPTER_H_
#define PDF_PDFIUM_PDFIUM_API_STRING_BUFFER_ADAPTER_H_
#include <stddef.h>
#include "base/macros.h"
#include "base/numerics/safe_math.h"
namespace chrome_pdf {
// Helper to deal with the fact that many PDFium APIs write the null-terminator
// into string buffers that are passed to them, but the PDF plugin likes to pass
// in std::strings / base::string16s, where one should not count on the internal
// string buffers to be null-terminated.
template <class StringType>
class PDFiumAPIStringBufferAdapter {
public:
// |str| is the string to write into.
// |expected_size| is the number of characters the PDFium API will write,
// including the null-terminator. It should be at least 1.
// |check_expected_size| whether to check the actual number of characters
// written into |str| against |expected_size| when calling Close().
PDFiumAPIStringBufferAdapter(StringType* str,
size_t expected_size,
bool check_expected_size);
~PDFiumAPIStringBufferAdapter();
// Returns a pointer to |str_|'s buffer. The buffer's size is large enough to
// hold |expected_size_| + 1 characters, so the PDFium API that uses the
// pointer has space to write a null-terminator.
void* GetData();
// Resizes |str_| to |actual_size| - 1 characters, thereby removing the extra
// null-terminator. This must be called prior to the adapter's destruction.
// The pointer returned by GetData() should be considered invalid.
void Close(size_t actual_size);
template <typename IntType>
void Close(IntType actual_size) {
Close(base::checked_cast<size_t>(actual_size));
}
private:
StringType* const str_;
void* const data_;
const size_t expected_size_;
const bool check_expected_size_;
bool is_closed_;
DISALLOW_COPY_AND_ASSIGN(PDFiumAPIStringBufferAdapter);
};
// Helper to deal with the fact that many PDFium APIs write the null-terminator
// into string buffers that are passed to them, but the PDF plugin likes to pass
// in std::strings / base::string16s, where one should not count on the internal
// string buffers to be null-terminated. This version is suitable for APIs that
// work in terms of number of bytes instead of the number of characters.
template <class StringType>
class PDFiumAPIStringBufferSizeInBytesAdapter {
public:
// |str| is the string to write into.
// |expected_size| is the number of bytes the PDFium API will write,
// including the null-terminator. It should be at least the size of a
// character in bytes.
// |check_expected_size| whether to check the actual number of bytes
// written into |str| against |expected_size| when calling Close().
PDFiumAPIStringBufferSizeInBytesAdapter(StringType* str,
size_t expected_size,
bool check_expected_size);
~PDFiumAPIStringBufferSizeInBytesAdapter();
// Returns a pointer to |str_|'s buffer. The buffer's size is large enough to
// hold |expected_size_| + sizeof(StringType::value_type) bytes, so the PDFium
// API that uses the pointer has space to write a null-terminator.
void* GetData();
// Resizes |str_| to |actual_size| - sizeof(StringType::value_type) bytes,
// thereby removing the extra null-terminator. This must be called prior to
// the adapter's destruction. The pointer returned by GetData() should be
// considered invalid.
void Close(size_t actual_size);
template <typename IntType>
void Close(IntType actual_size) {
Close(base::checked_cast<size_t>(actual_size));
}
private:
PDFiumAPIStringBufferAdapter<StringType> adapter_;
};
} // namespace chrome_pdf
#endif // PDF_PDFIUM_PDFIUM_API_STRING_BUFFER_ADAPTER_H_