Fixed a bug in file reading

PiperOrigin-RevId: 674498290

internal/platform/implementation/windows/file.cc

@@ -14,14 +14,15 @@
 
 #include "internal/platform/implementation/windows/file.h"
 
-#include <algorithm>
 #include <cstddef>
+#include <cstdint>
 #include <ios>
 #include <memory>
 #include <string>
 
 #include "absl/memory/memory.h"
 #include "absl/strings/string_view.h"
+#include "internal/platform/byte_array.h"
 #include "internal/platform/exception.h"
 #include "internal/platform/implementation/windows/utils.h"
 #include "internal/platform/logging.h"
@@ -30,13 +31,12 @@ namespace nearby {
 namespace windows {
 
 // InputFile
-std::unique_ptr<IOFile> IOFile::CreateInputFile(
-    const absl::string_view file_path, size_t size) {
+std::unique_ptr<IOFile> IOFile::CreateInputFile(absl::string_view file_path,
+                                                size_t size) {
   return absl::WrapUnique(new IOFile(file_path, size));
 }
 
-IOFile::IOFile(const absl::string_view file_path, size_t size)
-    : path_(file_path) {
+IOFile::IOFile(absl::string_view file_path, size_t size) : path_(file_path) {
   // Always open input file path as wide string on Windows platform.
   std::wstring wide_path = string_to_wstring(std::string(file_path));
   file_.open(wide_path, std::ios::binary | std::ios::in | std::ios::ate);
@@ -46,17 +46,17 @@ IOFile::IOFile(const absl::string_view file_path, size_t size)
     // Unsure why it consistently returns -1 when the file size exceeds 2GB. If
     // obtaining the file size through tellg fails, use the size provided
     // in the parameters.
-     total_size_ = size;
+    total_size_ = size;
   }
 
   file_.seekg(0);
 }
 
-std::unique_ptr<IOFile> IOFile::CreateOutputFile(const absl::string_view path) {
+std::unique_ptr<IOFile> IOFile::CreateOutputFile(absl::string_view path) {
   return std::unique_ptr<IOFile>(new IOFile(path));
 }
 
-IOFile::IOFile(const absl::string_view file_path)
+IOFile::IOFile(absl::string_view file_path)
     : file_(), path_(file_path), total_size_(0) {
   // Always open input file path as wide string on Windows platform.
   std::wstring wide_path = string_to_wstring(path_);
@@ -73,18 +73,20 @@ ExceptionOr<ByteArray> IOFile::Read(std::int64_t size) {
       return ExceptionOr<ByteArray>{Exception::kIo};
     }
 
-    if (file_.peek() == EOF) {
+    if (file_.eof()) {
       return ExceptionOr<ByteArray>{ByteArray{}};
     }
 
-    ByteArray bytes(size);
-    std::unique_ptr<char[]> read_bytes{new char[size]};
-    file_.read(read_bytes.get(), static_cast<ptrdiff_t>(size));
+    if (buffer_.size() < size) {
+      buffer_.resize(size);
+    }
+
+    file_.read(buffer_.data(), static_cast<ptrdiff_t>(size));
     auto num_bytes_read = file_.gcount();
     if (num_bytes_read == 0) {
       return ExceptionOr<ByteArray>{Exception::kIo};
     }
-    return ExceptionOr<ByteArray>(ByteArray(read_bytes.get(), num_bytes_read));
+    return ExceptionOr<ByteArray>(ByteArray(buffer_.data(), num_bytes_read));
   } catch (...) {
     NEARBY_LOGS(ERROR) << "Fail to read";
     return ExceptionOr<ByteArray>{Exception::kIo};

internal/platform/implementation/windows/file.h

@@ -15,12 +15,14 @@
 #ifndef PLATFORM_IMPL_WINDOWS_FILE_H_
 #define PLATFORM_IMPL_WINDOWS_FILE_H_
 
+#include <cstddef>
 #include <cstdint>
 #include <fstream>
 #include <memory>
 #include <string>
 
 #include "absl/strings/string_view.h"
+#include "internal/platform/byte_array.h"
 #include "internal/platform/exception.h"
 #include "internal/platform/implementation/input_file.h"
 #include "internal/platform/implementation/output_file.h"
@@ -30,10 +32,10 @@ namespace windows {
 
 class IOFile final : public api::InputFile, public api::OutputFile {
  public:
-  static std::unique_ptr<IOFile> CreateInputFile(
-      const absl::string_view file_path, size_t size);
+  static std::unique_ptr<IOFile> CreateInputFile(absl::string_view file_path,
+                                                 size_t size);
 
-  static std::unique_ptr<IOFile> CreateOutputFile(const absl::string_view path);
+  static std::unique_ptr<IOFile> CreateOutputFile(absl::string_view path);
 
   ExceptionOr<ByteArray> Read(std::int64_t size) override;
 
@@ -46,11 +48,12 @@ class IOFile final : public api::InputFile, public api::OutputFile {
   Exception Flush() override;
 
  private:
-  explicit IOFile(const absl::string_view file_path, size_t size);
-  explicit IOFile(const absl::string_view file_path);
+  explicit IOFile(absl::string_view file_path, size_t size);
+  explicit IOFile(absl::string_view file_path);
 
   std::fstream file_;
   std::string path_;
+  std::string buffer_;
   std::int64_t total_size_;
 };