// Copyright 2015 The Chromium OS Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef CHROMIUMOS_WIDE_PROFILING_DATA_READER_H_
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#define CHROMIUMOS_WIDE_PROFILING_DATA_READER_H_
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#include <stddef.h>
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#include <stdint.h>
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#include "binary_data_utils.h"
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#include "compat/string.h"
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namespace quipper {
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class DataReader {
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public:
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DataReader() : is_cross_endian_(false) {}
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virtual ~DataReader() {}
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// Moves the data read pointer to |offset| bytes from the beginning of the
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// data.
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virtual void SeekSet(size_t offset) = 0;
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// Returns the position of the data read pointer, in bytes from the beginning
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// of the data.
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virtual size_t Tell() const = 0;
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virtual size_t size() const { return size_; }
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// Reads raw data into |dest|. Returns true if it managed to read |size|
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// bytes.
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virtual bool ReadData(const size_t size, void* dest) = 0;
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// Reads raw data into a string.
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virtual bool ReadDataString(const size_t size, string* dest);
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// Like ReadData(), but prints an error if it doesn't read all |size| bytes.
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virtual bool ReadDataValue(const size_t size, const string& value_name,
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void* dest);
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// Read integers with endian swapping.
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bool ReadUint16(uint16_t* value) { return ReadIntValue(value); }
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bool ReadUint32(uint32_t* value) { return ReadIntValue(value); }
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bool ReadUint64(uint64_t* value) { return ReadIntValue(value); }
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// Read a string. Returns true if it managed to read |size| bytes (excluding
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// null terminator). The actual string may be shorter than the number of bytes
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// requested.
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virtual bool ReadString(const size_t size, string* str) = 0;
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// Reads a string from data into |dest| at the current offset. The string in
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// data is prefixed with a 32-bit size field. The size() of |*dest| after the
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// read will be the null-terminated string length of the underlying string
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// data, and not necessarily the same as the size field in the data.
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bool ReadStringWithSizeFromData(string* dest);
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bool is_cross_endian() const { return is_cross_endian_; }
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void set_is_cross_endian(bool value) { is_cross_endian_ = value; }
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protected:
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// Size of the data source.
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size_t size_;
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private:
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// Like ReadData(), but used specifically to read integers. Will swap byte
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// order if necessary.
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// For type-safety this one private and let public member functions call it.
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template <typename T>
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bool ReadIntValue(T* dest) {
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if (!ReadData(sizeof(T), dest)) return false;
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*dest = MaybeSwap(*dest, is_cross_endian_);
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return true;
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}
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// For cross-endian data reading.
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bool is_cross_endian_;
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};
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} // namespace quipper
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#endif // CHROMIUMOS_WIDE_PROFILING_DATA_READER_H_
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