gemma.cpp/io/io.h

119 lines
3.7 KiB
C++

// Copyright 2024 Google LLC
// SPDX-License-Identifier: Apache-2.0
//
// 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
//
// https://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.
#ifndef THIRD_PARTY_GEMMA_CPP_COMPRESSION_IO_H_
#define THIRD_PARTY_GEMMA_CPP_COMPRESSION_IO_H_
#include <stddef.h>
#include <stdint.h>
#include <memory>
#include <string>
#include <utility> // std::move
#include "util/allocator.h"
#include "hwy/base.h"
namespace gcpp {
// Forward-declare to break the circular dependency: OpenFileOrNull returns
// File and has a Path argument, and Path::Exists calls OpenFileOrNull. We
// prefer to define Exists inline because there are multiple io*.cc files.
struct Path;
using MapPtr = AlignedPtr<const uint8_t[]>;
// Abstract base class enables multiple I/O backends in the same binary.
class File {
public:
File() = default;
virtual ~File() = default;
// Noncopyable.
File(const File& other) = delete;
const File& operator=(const File& other) = delete;
// Returns size in bytes or 0.
virtual uint64_t FileSize() const = 0;
// Returns true if all the requested bytes were read.
virtual bool Read(uint64_t offset, uint64_t size, void* to) const = 0;
// Returns true if all the requested bytes were written.
virtual bool Write(const void* from, uint64_t size, uint64_t offset) = 0;
// Maps the entire file into read-only memory or returns nullptr on failure.
// We do not support offsets because Windows requires them to be a multiple of
// the allocation granularity, which is 64 KiB. Some implementations may fail
// if the file is zero-sized and return a nullptr.
virtual MapPtr Map() = 0;
};
// Returns nullptr on failure. `mode` is either "r" or "w+". This is not just
// named 'OpenFile' to avoid a conflict with Windows.h #define.
std::unique_ptr<File> OpenFileOrNull(const Path& filename, const char* mode);
// Wrapper for strings representing a path name. Differentiates vs. arbitrary
// strings and supports shortening for display purposes.
struct Path {
Path() {}
explicit Path(const char* p) : path(p) {}
explicit Path(std::string p) : path(std::move(p)) {}
Path& operator=(const char* other) {
path = other;
return *this;
}
std::string Shortened() const {
constexpr size_t kMaxLen = 48;
constexpr size_t kCutPoint = kMaxLen / 2 - 5;
if (path.size() > kMaxLen) {
return std::string(begin(path), begin(path) + kCutPoint) + " ... " +
std::string(end(path) - kCutPoint, end(path));
}
if (path.empty()) return "[no path specified]";
return path;
}
bool Empty() const { return path.empty(); }
// Returns whether the file existed when this was called.
bool Exists() const { return !!OpenFileOrNull(*this, "r"); }
std::string path;
};
// Aborts on error.
static inline HWY_MAYBE_UNUSED std::string ReadFileToString(const Path& path) {
std::unique_ptr<File> file = OpenFileOrNull(path, "r");
if (!file) {
HWY_ABORT("Failed to open %s", path.path.c_str());
}
const size_t size = file->FileSize();
if (size == 0) {
HWY_ABORT("Empty file %s", path.path.c_str());
}
std::string content(size, ' ');
if (!file->Read(0, size, content.data())) {
HWY_ABORT("Failed to read %s", path.path.c_str());
}
return content;
}
} // namespace gcpp
#endif // THIRD_PARTY_GEMMA_CPP_COMPRESSION_IO_H_