1 files changed, 153 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/jxl/base/file_io.h b/third_party/jpeg-xl/lib/jxl/base/file_io.h
new file mode 100644
index 0000000000..64d5860915
--- /dev/null
+++ b/third_party/jpeg-xl/lib/jxl/base/file_io.h
@@ -0,0 +1,153 @@
+// Copyright (c) the JPEG XL Project 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 LIB_JXL_BASE_FILE_IO_H_
+#define LIB_JXL_BASE_FILE_IO_H_
+
+// Helper functions for reading/writing files.
+
+#include <stdio.h>
+#include <sys/stat.h>
+
+#include <list>
+#include <string>
+#include <vector>
+
+#include "lib/jxl/base/compiler_specific.h"
+#include "lib/jxl/base/padded_bytes.h"
+#include "lib/jxl/base/status.h"
+
+namespace jxl {
+
+// Returns extension including the dot, or empty string if none. Assumes
+// filename is not a hidden file (e.g. ".bashrc"). May be called with a pathname
+// if the filename contains a dot and/or no other path component does.
+static inline std::string Extension(const std::string& filename) {
+  const size_t pos = filename.rfind('.');
+  if (pos == std::string::npos) return std::string();
+  return filename.substr(pos);
+}
+
+// RAII, ensures files are closed even when returning early.
+class FileWrapper {
+ public:
+  FileWrapper(const FileWrapper& other) = delete;
+  FileWrapper& operator=(const FileWrapper& other) = delete;
+
+  explicit FileWrapper(const std::string& pathname, const char* mode)
+      : file_(pathname == "-" ? (mode[0] == 'r' ? stdin : stdout)
+                              : fopen(pathname.c_str(), mode)),
+        close_on_delete_(pathname != "-") {
+#ifdef _WIN32
+    struct __stat64 s = {};
+    const int err = _stat64(pathname.c_str(), &s);
+    const bool is_file = (s.st_mode & S_IFREG) != 0;
+#else
+    struct stat s = {};
+    const int err = stat(pathname.c_str(), &s);
+    const bool is_file = S_ISREG(s.st_mode);
+#endif
+    if (err == 0 && is_file) {
+      size_ = s.st_size;
+    }
+  }
+
+  ~FileWrapper() {
+    if (file_ != nullptr && close_on_delete_) {
+      const int err = fclose(file_);
+      JXL_CHECK(err == 0);
+    }
+  }
+
+  // We intend to use FileWrapper as a replacement of FILE.
+  // NOLINTNEXTLINE(google-explicit-constructor)
+  operator FILE*() const { return file_; }
+
+  int64_t size() { return size_; }
+
+ private:
+  FILE* const file_;
+  bool close_on_delete_ = true;
+  int64_t size_ = -1;
+};
+
+template <typename ContainerType>
+static inline Status ReadFile(const std::string& pathname,
+                              ContainerType* JXL_RESTRICT bytes) {
+  FileWrapper f(pathname, "rb");
+  if (f == nullptr)
+    return JXL_FAILURE("Failed to open file for reading: %s", pathname.c_str());
+
+  // Get size of file in bytes
+  const int64_t size = f.size();
+  if (size < 0) {
+    // Size is unknown, loop reading chunks until EOF.
+    bytes->clear();
+    std::list<std::vector<uint8_t>> chunks;
+
+    size_t total_size = 0;
+    while (true) {
+      std::vector<uint8_t> chunk(16 * 1024);
+      const size_t bytes_read = fread(chunk.data(), 1, chunk.size(), f);
+      if (ferror(f) || bytes_read > chunk.size()) {
+        return JXL_FAILURE("Error reading %s", pathname.c_str());
+      }
+
+      chunk.resize(bytes_read);
+      total_size += bytes_read;
+      if (bytes_read != 0) {
+        chunks.emplace_back(std::move(chunk));
+      }
+      if (feof(f)) {
+        break;
+      }
+    }
+    bytes->resize(total_size);
+    size_t pos = 0;
+    for (const auto& chunk : chunks) {
+      // Needed in case ContainerType is std::string, whose data() is const.
+      char* bytes_writable = reinterpret_cast<char*>(&(*bytes)[0]);
+      memcpy(bytes_writable + pos, chunk.data(), chunk.size());
+      pos += chunk.size();
+    }
+  } else {
+    // Size is known, read the file directly.
+    bytes->resize(static_cast<size_t>(size));
+    size_t pos = 0;
+    while (pos < bytes->size()) {
+      // Needed in case ContainerType is std::string, whose data() is const.
+      char* bytes_writable = reinterpret_cast<char*>(&(*bytes)[0]);
+      const size_t bytes_read =
+          fread(bytes_writable + pos, 1, bytes->size() - pos, f);
+      if (bytes_read == 0) return JXL_FAILURE("Failed to read");
+      pos += bytes_read;
+    }
+    JXL_ASSERT(pos == bytes->size());
+  }
+  return true;
+}
+
+template <typename ContainerType>
+static inline Status WriteFile(const ContainerType& bytes,
+                               const std::string& pathname) {
+  FileWrapper f(pathname, "wb");
+  if (f == nullptr)
+    return JXL_FAILURE("Failed to open file for writing: %s", pathname.c_str());
+
+  size_t pos = 0;
+  while (pos < bytes.size()) {
+    const size_t bytes_written =
+        fwrite(bytes.data() + pos, 1, bytes.size() - pos, f);
+    if (bytes_written == 0) return JXL_FAILURE("Failed to write");
+    pos += bytes_written;
+  }
+  JXL_ASSERT(pos == bytes.size());
+
+  return true;
+}
+
+}  // namespace jxl
+
+#endif  // LIB_JXL_BASE_FILE_IO_H_