Class: Mspack::ChmDecompressor

Inherits:
Object
  • Object
show all
Defined in:
lib/mspack/chm_decompressor.rb,
ext/mspack_native/chm_decompressor.c

Defined Under Namespace

Classes: File, Header

Constant Summary collapse

DEFAULT_BUFFER_SIZE = 
4096.freeze

Instance Method Summary collapse

Instance Method Details

#close(header) ⇒ Object 



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# File 'ext/mspack_native/chm_decompressor.c', line 115

VALUE chmd_close(VALUE self, VALUE header) {
  if (!CLASS_OF(header) == ChmDHeader) {
    rb_raise(rb_eTypeError, "Parameter must be a CHM decompression header");
  }

  struct decom_wrapper *wrapper;
  Data_Get_Struct(self, struct decom_wrapper, wrapper);

  struct mschmd_header *headerPtr;
  Data_Get_Struct(header, struct mschmd_header, headerPtr);

  wrapper->decom->close(wrapper->decom, headerPtr);
  return Qnil;
}

#extract(file, dir_or_buffer_size = DEFAULT_BUFFER_SIZE) ⇒ Object

Expects a ChmDecompressor::File and either a string, or a fixnum if a block is given.

If no block is given, it calls Mspack.ensure_path and extracts file, returning the absolute file path.

If a block is given, chunks of data are yielded with a maximum size given by the dir_or_buffer_size param. Buffer_size must be a multiple of DEFAULT_BUFFER_SIZE.



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# File 'lib/mspack/chm_decompressor.rb', line 16

def extract(file, dir_or_buffer_size = DEFAULT_BUFFER_SIZE)

  if block_given?
    buffer_size = dir_or_buffer_size

    if (buffer_size.fdiv(DEFAULT_BUFFER_SIZE).modulo(1) != 0)
      raise ArgumentError, 
        'Buffer_size must be a multiple of DEFAULT_BUFFER_SIZE'
    end

    a = 0
    b = 0
    did_yield = false
    buffer = "\0" * buffer_size

    extract_to_path(file) do |data|
      did_yield = false
      b = a + data.length - 1
      buffer[a..b] = data

      # full buffer - yield and reset
      if b + 1 == buffer_size 
        yield buffer[0..b]
        did_yield = true
        a = 0

      # last read if it's less than default size
      elsif data.length > 0 && data.length < DEFAULT_BUFFER_SIZE
        yield buffer[0..b]
        did_yield = true
      
      else
        a = b + 1
      end
    end

    # last read happened to be default size
    yield buffer[0..b] if !did_yield && b > 0

  else
    path = Mspack.ensure_path(file.filename, dir_or_buffer_size)
    extract_to_path(file, path)
    return path
  end
end

#extract_to_path(*args) ⇒ Object

Form 1: extract_to_path(file, outputPath)

Form 2: extract_to_path(file) { |data_chunk| do_something(data_chunk) }



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# File 'ext/mspack_native/chm_decompressor.c', line 137

VALUE chmd_extract_to_path(int argc, VALUE* argv, VALUE self) {
  VALUE file;
  VALUE outputPath;
  rb_scan_args(argc, argv, "11", &file, &outputPath);
  const char *pathStr;

  if (!CLASS_OF(file) == ChmDFile) {
    rb_raise(rb_eTypeError, "First parameter must be a CHM decompression file");
  }

  if (argc == 1) {
    rb_need_block();
    VALUE block = rb_block_proc();
    VALUE block_name = rb_funcall(block, rb_intern("object_id"), 0);
    VALUE block_name_str = rb_funcall(block_name, rb_intern("to_s"), 0);
    pathStr = StringValueCStr(block_name_str);
  }
  else {
    Check_Type(outputPath, T_STRING);
    pathStr = StringValueCStr(outputPath);
  }

  struct decom_wrapper *wrapper;
  Data_Get_Struct(self, struct decom_wrapper, wrapper);

  struct chmd_file_wrapper *headerWrapper;
  Data_Get_Struct(file, struct chmd_file_wrapper, headerWrapper);

  int result = 
    wrapper->decom->extract(wrapper->decom, headerWrapper->file, pathStr);

  return result == MSPACK_ERR_OK ? Qtrue : Qfalse;
}

#fast_find(header, filename) ⇒ Object 



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# File 'ext/mspack_native/chm_decompressor.c', line 183

VALUE chmd_fast_find(VALUE self, VALUE header, VALUE filename) {
  struct decom_wrapper *wrapper;
  Data_Get_Struct(self, struct decom_wrapper, wrapper);

  struct mschmd_header *headerPtr;
  Data_Get_Struct(header, struct mschmd_header, headerPtr);

  const char *filenameStr = StringValueCStr(filename);

  int structSize = sizeof(struct mschmd_file);
  struct mschmd_file *file = malloc(structSize);

  int result = wrapper->decom->fast_find(
    wrapper->decom, headerPtr, filenameStr, file, structSize);

  if (result != MSPACK_ERR_OK || file->length == 0) {
    free(file);
    return Qnil;
  }  

  file->filename = malloc(sizeof(char) * strlen(filenameStr) + 1);
  strcpy(file->filename, filenameStr);

  struct chmd_file_wrapper *fileWrapper = 
    malloc(sizeof(struct chmd_file_wrapper));
  fileWrapper->is_fast_find = 1;
  fileWrapper->file = file;

  return Data_Wrap_Struct(ChmDFile, NULL, chmd_file_free, fileWrapper);
}

#fast_open(path) ⇒ Object 



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# File 'ext/mspack_native/chm_decompressor.c', line 179

VALUE chmd_fast_open(VALUE self, VALUE path) {
  return _open(self, path, 1);
}

#last_error ⇒ Object 



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# File 'ext/mspack_native/chm_decompressor.c', line 171

VALUE chmd_last_error(VALUE self) {
  struct decom_wrapper *wrapper;
  Data_Get_Struct(self, struct decom_wrapper, wrapper);

  int error = wrapper->decom->last_error(wrapper->decom);
  return _error_code_sym(error);
}

#open(path) ⇒ Object 



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# File 'ext/mspack_native/chm_decompressor.c', line 111

VALUE chmd_open(VALUE self, VALUE path) {
  return _open(self, path, 0);
}