というわけで、その次は Zlib::GzipReader#readpartial を次のように追加す
るのはどうでしょうか。
[ruby-dev:24066] のパッチを当てた後に当てるパッチです。
--- ext/zlib/zlib.c 2004-08-13 18:38:28.000000000 +0900
+++ ext/zlib/zlib.c-readpartial 2004-08-13 18:08:12.000000000 +0900
@@ -107,6 +107,8 @@
static void gzfile_reset _((struct gzfile*));
static void gzfile_close _((struct gzfile*, int));
static void gzfile_write_raw _((struct gzfile*));
+static VALUE gzfile_read_raw_partial _((VALUE));
+static VALUE gzfile_read_raw_rescue _((VALUE));
static VALUE gzfile_read_raw _((struct gzfile*));
static int gzfile_read_raw_ensure _((struct gzfile*, int));
static char *gzfile_read_raw_until_zero _((struct gzfile*, long));
@@ -1664,7 +1666,7 @@
#define OS_CODE OS_UNIX
#endif
-static ID id_write, id_read, id_flush, id_seek, id_close;
+static ID id_write, id_read, id_readpartial, id_flush, id_seek, id_close;
static VALUE cGzError, cNoFooter, cCRCError, cLengthError;
@@ -1787,18 +1789,41 @@
}
static VALUE
-gzfile_read_raw(gz)
- struct gzfile *gz;
+gzfile_read_raw_partial(arg)
+ VALUE arg;
{
+ struct gzfile *gz = (struct gzfile *)arg;
VALUE str;
- str = rb_funcall(gz->io, id_read, 1, INT2FIX(GZFILE_READ_SIZE));
- if (!NIL_P(str)) {
- Check_Type(str, T_STRING);
+ str = rb_funcall(gz->io, id_readpartial, 1, INT2FIX(GZFILE_READ_SIZE));
+ Check_Type(str, T_STRING);
+ return str;
+}
+
+static VALUE
+gzfile_read_raw_rescue(arg)
+ VALUE arg;
+{
+ struct gzfile *gz = (struct gzfile *)arg;
+ VALUE str = Qnil;
+ if (rb_obj_is_kind_of(ruby_errinfo, rb_eNoMethodError)) {
+ str = rb_funcall(gz->io, id_read, 1, INT2FIX(GZFILE_READ_SIZE));
+ if (!NIL_P(str)) {
+ Check_Type(str, T_STRING);
+ }
}
return str;
}
+static VALUE
+gzfile_read_raw(gz)
+ struct gzfile *gz;
+{
+ return rb_rescue2(gzfile_read_raw_partial, (VALUE)gz,
+ gzfile_read_raw_rescue, (VALUE)gz,
+ rb_eEOFError, rb_eNoMethodError, (VALUE)0);
+}
+
static int
gzfile_read_raw_ensure(gz, size)
struct gzfile *gz;
@@ -2113,6 +2138,54 @@
}
static VALUE
+gzfile_readpartial(gz, len, outbuf)
+ struct gzfile *gz;
+ int len;
+ VALUE outbuf;
+{
+ VALUE dst;
+
+ if (len < 0)
+ rb_raise(rb_eArgError, "negative length %d given", len);
+
+ if (!NIL_P(outbuf))
+ OBJ_TAINT(outbuf);
+
+ if (len == 0) {
+ if (NIL_P(outbuf))
+ return rb_str_new(0, 0);
+ else {
+ rb_str_resize(outbuf, 0);
+ return outbuf;
+ }
+ }
+ while (!ZSTREAM_IS_FINISHED(&gz->z) && gz->z.buf_filled == 0) {
+ gzfile_read_more(gz);
+ }
+ if (GZFILE_IS_FINISHED(gz)) {
+ if (!(gz->z.flags & GZFILE_FLAG_FOOTER_FINISHED)) {
+ gzfile_check_footer(gz);
+ }
+ if (!NIL_P(outbuf))
+ rb_str_resize(outbuf, 0);
+ rb_raise(rb_eEOFError, "End of file reached");
+ }
+
+ dst = zstream_shift_buffer(&gz->z, len);
+ gzfile_calc_crc(gz, dst);
+
+ if (NIL_P(outbuf)) {
+ OBJ_TAINT(dst); /* for safe */
+ return dst;
+ }
+ else {
+ rb_str_resize(outbuf, RSTRING(dst)->len);
+ memcpy(RSTRING(outbuf)->ptr, RSTRING(dst)->ptr, RSTRING(dst)->len);
+ return outbuf;
+ }
+}
+
+static VALUE
gzfile_read_all(gz)
struct gzfile *gz;
{
@@ -2940,6 +3013,30 @@
* See Zlib::GzipReader documentation for a description.
*/
static VALUE
+rb_gzreader_readpartial(argc, argv, obj)
+ int argc;
+ VALUE *argv;
+ VALUE obj;
+{
+ struct gzfile *gz = get_gzfile(obj);
+ VALUE vlen, outbuf;
+ int len;
+
+ rb_scan_args(argc, argv, "11", &vlen, &outbuf);
+
+ len = NUM2INT(vlen);
+ if (len < 0) {
+ rb_raise(rb_eArgError, "negative length %d given", len);
+ }
+ if (!NIL_P(outbuf))
+ Check_Type(outbuf, T_STRING);
+ return gzfile_readpartial(gz, len, outbuf);
+}
+
+/*
+ * See Zlib::GzipReader documentation for a description.
+ */
+static VALUE
rb_gzreader_getc(obj)
VALUE obj;
{
@@ -3340,6 +3437,7 @@
#if GZIP_SUPPORT
id_write = rb_intern("write");
id_read = rb_intern("read");
+ id_readpartial = rb_intern("readpartial");
id_flush = rb_intern("flush");
id_seek = rb_intern("seek");
id_close = rb_intern("close");
@@ -3398,6 +3496,7 @@
rb_define_method(cGzipReader, "rewind", rb_gzreader_rewind, 0);
rb_define_method(cGzipReader, "unused", rb_gzreader_unused, 0);
rb_define_method(cGzipReader, "read", rb_gzreader_read, -1);
+ rb_define_method(cGzipReader, "readpartial", rb_gzreader_readpartial, -1);
rb_define_method(cGzipReader, "getc", rb_gzreader_getc, 0);
rb_define_method(cGzipReader, "readchar", rb_gzreader_readchar, 0);
rb_define_method(cGzipReader, "each_byte", rb_gzreader_each_byte, 0);
ちなみに、
% gzip -9 < eval.c | ./ruby -rzlib -e '
STDOUT.sync = true
r, w = IO.pipe
w.sync = true
ilen = 0
Thread.new {
begin
loop {
w.print STDIN.sysread(1)
ilen += 1
Thread.pass
}
rescue EOFError
end
}
io = Zlib::GzipReader.new(r)
begin
loop { p [ilen, io.readpartial(4096)] }
rescue EOFError
end
'
などとやると、
[10, "/"]
[81, "*"]
[82, "*********************************************************************"]
[85, "\n"]
[86, "\n "]
[87, " "]
...
というように、辞書が成長していく感じが見えてなかなか楽しいです。
--
[田中 哲][たなか あきら][Tanaka Akira]