new classes for resource management

fairseq2n/src/fairseq2n/data/image/detail/jpeg_decompress_struct.cc

@@ -0,0 +1,26 @@
+// Copyright (c) Meta Platforms, Inc. and affiliates.error_ptr
+// All rights reserved.
+//
+// This source code is licensed under the BSD-style license found in the
+// LICENSE file in the root directory of this source tree.
+
+#include "fairseq2n/data/image/detail/jpeg_decompress_struct.h"
+
+#include <jpeglib.h>
+
+#include "fairseq2n/exception.h"
+#include "fairseq2n/detail/exception.h"
+
+namespace fairseq2n::detail {
+
+jpeg_decompress::jpeg_decompress() {}
+
+jpeg_decompress::~jpeg_decompress() {
+    jpeg_destroy_decompress(&cinfo);
+}
+
+jpeg_decompress_struct& jpeg_decompress::get() {
+    return cinfo;
+}
+
+} // namespace fairseq2n::detail

fairseq2n/src/fairseq2n/data/image/detail/jpeg_decompress_struct.h

@@ -0,0 +1,27 @@
+// Copyright (c) Meta Platforms, Inc. and affiliates.
+// All rights reserved.
+//
+// This source code is licensed under the BSD-style license found in the
+// LICENSE file in the root directory of this source tree.
+
+#pragma once
+
+#include <jpeglib.h>
+#include "fairseq2n/exception.h"
+
+namespace fairseq2n::detail {
+
+class jpeg_decompress {
+public:
+    jpeg_decompress();
+    ~jpeg_decompress();
+
+    jpeg_decompress_struct& get();
+
+private:
+    jpeg_decompress_struct cinfo;
+    jpeg_decompress(const jpeg_decompress&); 
+    jpeg_decompress& operator=(const jpeg_decompress&); 
+};
+
+} // namespace fairseq2n::detail

fairseq2n/src/fairseq2n/data/image/detail/png_read_struct.cc

@@ -0,0 +1,40 @@
+// Copyright (c) Meta Platforms, Inc. and affiliates.
+// All rights reserved.
+//
+// This source code is licensed under the BSD-style license found in the
+// LICENSE file in the root directory of this source tree.
+
+#include "fairseq2n/data/image/detail/png_read_struct.h"
+
+#include "fairseq2n/exception.h"
+#include "fairseq2n/detail/exception.h"
+
+namespace fairseq2n::detail {
+
+png_read::png_read() : png_ptr(nullptr), info_ptr(nullptr) {
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
+    if (png_ptr == nullptr) {
+        throw internal_error("Failed to create PNG read struct.");
+    }
+    info_ptr = png_create_info_struct(png_ptr);
+    if (info_ptr == nullptr) {
+        png_destroy_read_struct(&png_ptr, nullptr, nullptr);
+        throw internal_error("Failed to create PNG info struct.");
+    }
+}
+
+png_read::~png_read() {
+    if (png_ptr) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, nullptr);
+    }
+}
+
+png_structp png_read::getPngPtr() const {
+    return png_ptr;
+}
+
+png_infop png_read::getInfoPtr() const {
+    return info_ptr;
+}
+
+} // namespace fairseq2n::detail

fairseq2n/src/fairseq2n/data/image/detail/png_read_struct.h

@@ -0,0 +1,28 @@
+// Copyright (c) Meta Platforms, Inc. and affiliates.
+// All rights reserved.
+//
+// This source code is licensed under the BSD-style license found in the
+// LICENSE file in the root directory of this source tree.
+
+#pragma once
+
+#include <png.h>
+
+namespace fairseq2n::detail {
+
+class png_read{
+public:
+    png_read();
+    ~png_read();
+
+    png_structp getPngPtr() const;
+    png_infop getInfoPtr() const;
+
+private:
+    png_structp png_ptr;
+    png_infop info_ptr;
+    png_read(const png_read&);
+    png_read& operator=(const png_read&); 
+};
+
+} // namespace fairseq2n::detail

fairseq2n/src/fairseq2n/data/image/image_decoder.cc

@@ -9,17 +9,17 @@
 #include <cstdint>
 #include <exception>
 #include <stdexcept>
-#include <iostream>
 
 #include <ATen/Functions.h>
 #include <ATen/Tensor.h>
-#include <setjmp.h>
+#include <csetjmp>
 
 #include "fairseq2n/exception.h"
 #include "fairseq2n/float.h"
 #include "fairseq2n/fmt.h"
 #include "fairseq2n/memory.h"
-#include "fairseq2n/span.h"
+#include "fairseq2n/data/image/detail/png_read_struct.h"
+#include "fairseq2n/data/image/detail/jpeg_decompress_struct.h"
 #include "fairseq2n/data/detail/tensor_helpers.h"
 #include "fairseq2n/detail/exception.h"
 
@@ -67,15 +67,9 @@ image_decoder::operator()(data &&d) const
 data
 image_decoder::decode_png(const memory_block &block) const 
 {
-    png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
-    if (png_ptr == nullptr) {
-        throw_<internal_error>("Failed to create PNG read struct.");
-    }
-    png_infop info_ptr = png_create_info_struct(png_ptr);
-    if (info_ptr == nullptr) {
-        png_destroy_read_struct(&png_ptr, nullptr, nullptr);
-        throw_<internal_error>("Failed to create PNG info struct.");
-    }
+    png_read pngReadStruct; 
+    png_structp png_ptr = pngReadStruct.getPngPtr();
+    png_infop info_ptr = pngReadStruct.getInfoPtr();
 
     auto data_ptr = png_const_bytep(block.data());
     auto data_len = block.size();
@@ -162,25 +156,25 @@ image_decoder::decode_png(const memory_block &block) const
 data
 image_decoder::decode_jpeg(const memory_block &block) const 
 {
+    jpeg_decompress jpegDecompressStruct;
+    jpeg_decompress_struct cinfo = jpegDecompressStruct.get();
+
+    auto data_ptr = block.data();
+    auto data_len = block.size();
+
     struct custom_error_mgr {
         struct jpeg_error_mgr pub;	// Public fields
         jmp_buf setjmp_buffer;	// Return to caller 
     };
-    typedef struct custom_error_mgr * error_ptr;
-
-    auto data_ptr = block.data();
-    auto data_len = block.size();
-
-    // Set up decompression process
-    struct jpeg_decompress_struct cinfo = {};
     struct custom_error_mgr jerr = {};
+    typedef struct custom_error_mgr * error_ptr;
     cinfo.err = jpeg_std_error(&jerr.pub);
-    // error_exit is called by libjpeg when fatal error occurs
+    // error_exit is called by libjpeg when a fatal error occurs
     jerr.pub.error_exit = [](j_common_ptr cinfo) {
-        // cinfo->err really points to a custom_error_mgr struct, so coerce pointer 
-        error_ptr myerr = (error_ptr) cinfo->err;
-        (*cinfo->err->output_message) (cinfo);
-        // Return control to the setjmp point 
+        // Coerce pointer to custom_error_mgr struct
+        auto myerr = reinterpret_cast<error_ptr>(cinfo->err);
+        (*cinfo->err->output_message)(cinfo);
+        // Return control to the setjmp point
         longjmp(myerr->setjmp_buffer, 1);
     };
     // If an error occurs, error_exit will longjmp back to setjmp