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refactor jpeg reader to close fd after read - refs #1783

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This commit is contained in:
Dane Springmeyer 2013-04-09 18:36:02 -07:00
parent 6e29ceb55f
commit 16e2e8a06f
1 changed files with 47 additions and 22 deletions
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69
src/jpeg_reader.cpp
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@ -42,22 +42,34 @@ namespace mapnik
{
class jpeg_reader : public image_reader
{
struct file_closer
struct jpeg_file_guard
{
void operator() (FILE * file)
{
if (file != 0) fclose(file);
}
jpeg_file_guard(FILE * fd)
: fd_(fd) {}
~jpeg_file_guard()
{
if (fd_) fclose(fd_);
}
FILE * fd_;
};
struct jpeg_info_guard
{
jpeg_info_guard(jpeg_decompress_struct * cinfo)
: i_(cinfo) {}
~jpeg_info_guard()
{
jpeg_destroy_decompress(i_);
}
jpeg_decompress_struct * i_;
};
typedef boost::shared_ptr<FILE> file_ptr;
private:
std::string file_name_;
unsigned width_;
unsigned height_;
jpeg_decompress_struct cinfo;
jpeg_error_mgr jerr;
file_ptr file_;
public:
explicit jpeg_reader(std::string const& fileName);
~jpeg_reader();
@ -83,21 +95,17 @@ const bool registered = register_image_reader("jpeg",create_jpeg_reader);
jpeg_reader::jpeg_reader(std::string const& fileName)
: file_name_(fileName),
width_(0),
height_(0),
file_()
height_(0)
{
init();
}
jpeg_reader::~jpeg_reader()
{
jpeg_destroy_decompress(&cinfo);
}
jpeg_reader::~jpeg_reader() {}
void jpeg_reader::on_error(j_common_ptr cinfo)
{
(*cinfo->err->output_message)(cinfo);
jpeg_destroy(cinfo);
//(*cinfo->err->output_message)(cinfo);
//jpeg_destroy(cinfo);
throw image_reader_exception("JPEG Reader: libjpeg could not read image");
}
@ -110,13 +118,17 @@ void jpeg_reader::init()
{
FILE * fp = fopen(file_name_.c_str(),"rb");
if (!fp) throw image_reader_exception("JPEG Reader: cannot open image file " + file_name_);
file_ = boost::shared_ptr<FILE>(fp,file_closer());
jpeg_file_guard guard(fp);
jpeg_decompress_struct cinfo;
jpeg_info_guard iguard(&cinfo);
jpeg_error_mgr jerr;
cinfo.err = jpeg_std_error(&jerr);
jerr.error_exit = on_error;
jerr.output_message = on_error_message;
jpeg_create_decompress(&cinfo);
jpeg_stdio_src(&cinfo, &*file_);
jpeg_read_header(&cinfo, TRUE);
jpeg_stdio_src(&cinfo, fp);
int ret = jpeg_read_header(&cinfo, TRUE);
if (ret != JPEG_HEADER_OK) throw image_reader_exception("JPEG Reader: failed to read header in " + file_name_);
jpeg_start_decompress(&cinfo);
width_ = cinfo.output_width;
height_ = cinfo.output_height;
@ -127,7 +139,6 @@ void jpeg_reader::init()
}
if (cinfo.output_width == 0 || cinfo.output_height == 0)
{
jpeg_destroy_decompress (&cinfo);
throw image_reader_exception("JPEG Reader: failed to read image size of " + file_name_);
}
}
@ -144,6 +155,20 @@ unsigned jpeg_reader::height() const
void jpeg_reader::read(unsigned x0, unsigned y0, image_data_32& image)
{
FILE * fp = fopen(file_name_.c_str(),"rb");
if (!fp) throw image_reader_exception("JPEG Reader: cannot open image file " + file_name_);
jpeg_file_guard guard(fp);
jpeg_decompress_struct cinfo;
jpeg_info_guard iguard(&cinfo);
jpeg_error_mgr jerr;
cinfo.err = jpeg_std_error(&jerr);
jerr.error_exit = on_error;
jerr.output_message = on_error_message;
jpeg_create_decompress(&cinfo);
jpeg_stdio_src(&cinfo, fp);
int ret = jpeg_read_header(&cinfo, TRUE);
if (ret != JPEG_HEADER_OK) throw image_reader_exception("JPEG Reader: failed to read header in " + file_name_);
jpeg_start_decompress(&cinfo);
JSAMPARRAY buffer;
int row_stride;
unsigned char a,r,g,b;
@ -179,7 +204,7 @@ void jpeg_reader::read(unsigned x0, unsigned y0, image_data_32& image)
}
++row;
}
jpeg_destroy_decompress(&cinfo);
jpeg_finish_decompress(&cinfo);
}
}