class Zlib::GzipWriter
Zlib::GzipWriter is a class for writing gzipped files. GzipWriter should be used with an instance of IO, or IO-like, object.
Following two example generate the same result.
Zlib::GzipWriter.open('hoge.gz') do |gz| gz.write 'jugemu jugemu gokou no surikire...' end File.open('hoge.gz', 'w') do |f| gz = Zlib::GzipWriter.new(f) gz.write 'jugemu jugemu gokou no surikire...' gz.close end
To make like gzip(1) does, run following:
orig = 'hoge.txt' Zlib::GzipWriter.open('hoge.gz') do |gz| gz.mtime = File.mtime(orig) gz.orig_name = orig gz.write IO.binread(orig) end
NOTE: Due to the limitation of Ruby's finalizer, you must explicitly close GzipWriter objects by Zlib::GzipFile#close etc. Otherwise, GzipWriter will be not able to write the gzip footer and will generate a broken gzip file.
Public Class Methods
Creates a GzipWriter object associated with
io
. level
and strategy
should be the
same as the arguments of Zlib::Deflate.new. The GzipWriter object writes gzipped data to
io
. io
must respond to the write
method that behaves the same as IO#write.
The options
hash may be used to set the encoding of the data.
:external_encoding
, :internal_encoding
and
:encoding
may be set as in IO.new.
static VALUE rb_gzwriter_initialize(int argc, VALUE *argv, VALUE obj) { struct gzfile *gz; VALUE io, level, strategy, opt = Qnil; int err; if (argc > 1) { opt = rb_check_convert_type(argv[argc-1], T_HASH, "Hash", "to_hash"); if (!NIL_P(opt)) argc--; } rb_scan_args(argc, argv, "12", &io, &level, &strategy); Data_Get_Struct(obj, struct gzfile, gz); /* this is undocumented feature of zlib */ gz->level = ARG_LEVEL(level); err = deflateInit2(&gz->z.stream, gz->level, Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL, ARG_STRATEGY(strategy)); if (err != Z_OK) { raise_zlib_error(err, gz->z.stream.msg); } gz->io = io; ZSTREAM_READY(&gz->z); rb_gzfile_ecopts(gz, opt); if (rb_respond_to(io, id_path)) { gz->path = rb_funcall(gz->io, id_path, 0); rb_define_singleton_method(obj, "path", rb_gzfile_path, 0); } return obj; }
Opens a file specified by filename
for writing gzip compressed
data, and returns a GzipWriter object
associated with that file. Further details of this method are found in ::new and Zlib::GzipFile.wrap.
static VALUE rb_gzwriter_s_open(int argc, VALUE *argv, VALUE klass) { return gzfile_s_open(argc, argv, klass, "wb"); }
Public Instance Methods
Document-method: << Same as IO.
#define rb_gzwriter_addstr rb_io_addstr
Specify the comment (str
) in the gzip header.
static VALUE rb_gzfile_set_comment(VALUE obj, VALUE str) { struct gzfile *gz = get_gzfile(obj); VALUE s; char *p; if (gz->z.flags & GZFILE_FLAG_HEADER_FINISHED) { rb_raise(cGzError, "header is already written"); } s = rb_str_dup(rb_str_to_str(str)); p = memchr(RSTRING_PTR(s), '\0', RSTRING_LEN(s)); if (p) { rb_str_resize(s, p - RSTRING_PTR(s)); } gz->comment = s; return str; }
Flushes all the internal buffers of the GzipWriter object. The meaning of
flush
is same as in Zlib::Deflate#deflate.
Zlib::SYNC_FLUSH
is used if flush
is omitted. It
is no use giving flush Zlib::NO_FLUSH
.
static VALUE rb_gzwriter_flush(int argc, VALUE *argv, VALUE obj) { struct gzfile *gz = get_gzfile(obj); VALUE v_flush; int flush; rb_scan_args(argc, argv, "01", &v_flush); flush = FIXNUMARG(v_flush, Z_SYNC_FLUSH); if (flush != Z_NO_FLUSH) { /* prevent Z_BUF_ERROR */ zstream_run(&gz->z, (Bytef*)"", 0, flush); } gzfile_write_raw(gz); if (rb_respond_to(gz->io, id_flush)) { rb_funcall(gz->io, id_flush, 0); } return obj; }
Specify the modification time (mtime
) in the gzip header.
Using a Fixnum or Integer
static VALUE rb_gzfile_set_mtime(VALUE obj, VALUE mtime) { struct gzfile *gz = get_gzfile(obj); VALUE val; if (gz->z.flags & GZFILE_FLAG_HEADER_FINISHED) { rb_raise(cGzError, "header is already written"); } val = rb_Integer(mtime); gz->mtime = NUM2UINT(val); return mtime; }
Specify the original name (str
) in the gzip header.
static VALUE rb_gzfile_set_orig_name(VALUE obj, VALUE str) { struct gzfile *gz = get_gzfile(obj); VALUE s; char *p; if (gz->z.flags & GZFILE_FLAG_HEADER_FINISHED) { rb_raise(cGzError, "header is already written"); } s = rb_str_dup(rb_str_to_str(str)); p = memchr(RSTRING_PTR(s), '\0', RSTRING_LEN(s)); if (p) { rb_str_resize(s, p - RSTRING_PTR(s)); } gz->orig_name = s; return str; }
Total number of input bytes read so far.
static VALUE rb_gzfile_total_in(VALUE obj) { return rb_uint2inum(get_gzfile(obj)->z.stream.total_in); }
Same as IO.
#define rb_gzwriter_print rb_io_print
Same as IO.
#define rb_gzwriter_printf rb_io_printf
Same as IO.
static VALUE rb_gzwriter_putc(VALUE obj, VALUE ch) { struct gzfile *gz = get_gzfile(obj); char c = NUM2CHR(ch); gzfile_write(gz, (Bytef*)&c, 1); return ch; }
Same as IO.
#define rb_gzwriter_puts rb_io_puts
Total number of input bytes read so far.
static VALUE rb_gzfile_total_in(VALUE obj) { return rb_uint2inum(get_gzfile(obj)->z.stream.total_in); }
Same as IO.
static VALUE rb_gzwriter_write(VALUE obj, VALUE str) { struct gzfile *gz = get_gzfile(obj); if (!RB_TYPE_P(str, T_STRING)) str = rb_obj_as_string(str); if (gz->enc2 && gz->enc2 != rb_ascii8bit_encoding()) { str = rb_str_conv_enc(str, rb_enc_get(str), gz->enc2); } gzfile_write(gz, (Bytef*)RSTRING_PTR(str), RSTRING_LEN(str)); return INT2FIX(RSTRING_LEN(str)); }