* transcode_data.h (rb_transcoding): remove stateful field.

  add state field.
  (TRANSCODING_STATE): defined.
  (rb_transcoder): add fields: state_size, state_init_func,
  state_fini_func.
  change rb_transcoding* argument to void*.

* transcode.c (transcode_restartable0): use TRANSCODING_STATE for
  first arguments of transcoder functions.
  (rb_transcoding_open_by_transcoder): initialize state field.
  (rb_transcoding_close): finalize state field.

* tool/transcode-tblgen.rb: provide state size/init/fini.

* enc/trans/newline.trans (universal_newline_init): defined.
  (fun_so_universal_newline): take void* as a state pointer.
  (rb_universal_newline): provide state size/init/fini.
  (rb_crlf_newline): ditto.
  (rb_cr_newline): ditto.

* enc/trans/iso2022.trans (iso2022jp_init): defined.
  (fun_si_iso2022jp_to_eucjp): take void* as a state pointer.
  (fun_so_iso2022jp_to_eucjp): ditto.
  (fun_so_eucjp_to_iso2022jp): ditto.
  (iso2022jp_reset_sequence_size): ditto.
  (finish_eucjp_to_iso2022jp): ditto.
  (rb_ISO_2022_JP_to_EUC_JP): provide state size/init/fini.
  (rb_EUC_JP_to_ISO_2022_JP): ditto.

* enc/trans/utf_16_32.trans (fun_so_from_utf_16be): take void* as a
  state pointer.
  (fun_so_to_utf_16be): ditto.
  (fun_so_from_utf_16le): ditto.
  (fun_so_to_utf_16le): ditto.
  (fun_so_from_utf_32be): ditto.
  (fun_so_to_utf_32be): ditto.
  (fun_so_from_utf_32le): ditto.
  (fun_so_to_utf_32le): ditto.
  (rb_from_UTF_16BE): provide state size/init/fini.
  (rb_to_UTF_16BE): ditto.
  (rb_from_UTF_16LE): ditto.
  (rb_to_UTF_16LE): ditto.
  (rb_from_UTF_32BE): ditto.
  (rb_to_UTF_32BE): ditto.
  (rb_from_UTF_32LE): ditto.
  (rb_to_UTF_32LE): ditto.

* enc/trans/japanese.trans (fun_so_eucjp2sjis): take void* as a state
  pointer.
  (fun_so_sjis2eucjp): ditto.
  (rb_eucjp2sjis): provide state size/init/fini.
  (rb_sjis2eucjp): provide state size/init/fini.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@19096 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

8 files changed, 167 insertions, 62 deletions

diff --git a/ChangeLog b/ChangeLog
index 1ca202c77c..1f31bed33e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,58 @@
+Wed Sep  3 23:03:37 2008  Tanaka Akira  <akr@fsij.org>
+
+	* transcode_data.h (rb_transcoding): remove stateful field.
+	  add state field.
+	  (TRANSCODING_STATE): defined.
+	  (rb_transcoder): add fields: state_size, state_init_func,
+	  state_fini_func.
+	  change rb_transcoding* argument to void*.
+
+	* transcode.c (transcode_restartable0): use TRANSCODING_STATE for
+	  first arguments of transcoder functions.
+	  (rb_transcoding_open_by_transcoder): initialize state field.
+	  (rb_transcoding_close): finalize state field.
+
+	* tool/transcode-tblgen.rb: provide state size/init/fini.
+
+	* enc/trans/newline.trans (universal_newline_init): defined.
+	  (fun_so_universal_newline): take void* as a state pointer.
+	  (rb_universal_newline): provide state size/init/fini.
+	  (rb_crlf_newline): ditto.
+	  (rb_cr_newline): ditto.
+
+	* enc/trans/iso2022.trans (iso2022jp_init): defined.
+	  (fun_si_iso2022jp_to_eucjp): take void* as a state pointer.
+	  (fun_so_iso2022jp_to_eucjp): ditto.
+	  (fun_so_eucjp_to_iso2022jp): ditto.
+	  (iso2022jp_reset_sequence_size): ditto.
+	  (finish_eucjp_to_iso2022jp): ditto.
+	  (rb_ISO_2022_JP_to_EUC_JP): provide state size/init/fini.
+	  (rb_EUC_JP_to_ISO_2022_JP): ditto.
+
+	* enc/trans/utf_16_32.trans (fun_so_from_utf_16be): take void* as a
+	  state pointer.
+	  (fun_so_to_utf_16be): ditto.
+	  (fun_so_from_utf_16le): ditto.
+	  (fun_so_to_utf_16le): ditto.
+	  (fun_so_from_utf_32be): ditto.
+	  (fun_so_to_utf_32be): ditto.
+	  (fun_so_from_utf_32le): ditto.
+	  (fun_so_to_utf_32le): ditto.
+	  (rb_from_UTF_16BE): provide state size/init/fini.
+	  (rb_to_UTF_16BE): ditto.
+	  (rb_from_UTF_16LE): ditto.
+	  (rb_to_UTF_16LE): ditto.
+	  (rb_from_UTF_32BE): ditto.
+	  (rb_to_UTF_32BE): ditto.
+	  (rb_from_UTF_32LE): ditto.
+	  (rb_to_UTF_32LE): ditto.
+
+	* enc/trans/japanese.trans (fun_so_eucjp2sjis): take void* as a state
+	  pointer.
+	  (fun_so_sjis2eucjp): ditto.
+	  (rb_eucjp2sjis): provide state size/init/fini.
+	  (rb_sjis2eucjp): provide state size/init/fini.
+
 Wed Sep  3 22:31:11 2008  Yuki Sonoda (Yugui)  <yugui@yugui.jp>
 
 	* lib/mathn.rb (Integer): moved into prime.rb.
diff --git a/enc/trans/iso2022.trans b/enc/trans/iso2022.trans
index 49da2c3f6c..067611ebd0 100644
--- a/enc/trans/iso2022.trans
+++ b/enc/trans/iso2022.trans
@@ -27,10 +27,22 @@
 
 <%= transcode_generated_code %>
 
+#define G0_ASCII 0
+#define G0_JISX0208 1
+
+static int
+iso2022jp_init(void *statep)
+{
+    unsigned char *sp = statep;
+    *sp = G0_ASCII;
+    return 0;
+}
+
 static VALUE
-fun_si_iso2022jp_to_eucjp(rb_transcoding* t, const unsigned char* s, size_t l)
+fun_si_iso2022jp_to_eucjp(void *statep, const unsigned char *s, size_t l)
 {
-    if (t->stateful[0] == 0)
+    unsigned char *sp = statep;
+    if (*sp == G0_ASCII)
         return (VALUE)NOMAP;
     else if (0x21 <= s[0] && s[0] <= 0x7e)
         return (VALUE)iso2022jp_to_eucjp_jisx0208_rest;
@@ -39,14 +51,15 @@ fun_si_iso2022jp_to_eucjp(rb_transcoding* t, const unsigned char* s, size_t l)
 }
 
 static int
-fun_so_iso2022jp_to_eucjp(rb_transcoding* t, const unsigned char* s, size_t l, unsigned char* o)
+fun_so_iso2022jp_to_eucjp(void *statep, const unsigned char *s, size_t l, unsigned char* o)
 {
+    unsigned char *sp = statep;
     if (s[0] == 0x1b) {
         if (s[1] == '(') {
             switch (s[l-1]) {
               case 'B':
               case 'J':
-                t->stateful[0] = 0;
+                *sp = G0_ASCII;
                 break;
             }
         }
@@ -54,7 +67,7 @@ fun_so_iso2022jp_to_eucjp(rb_transcoding* t, const unsigned char* s, size_t l, u
             switch (s[l-1]) {
               case '@':
               case 'B':
-                t->stateful[0] = 1;
+                *sp = G0_JISX0208;
                 break;
             }
         }
@@ -75,31 +88,28 @@ rb_ISO_2022_JP_to_EUC_JP = {
     3, /* max_input */
     3, /* max_output */
     stateful_decoder, /* stateful_type */
+    1, iso2022jp_init, iso2022jp_init, /* state_size, state_init, state_fini */
     NULL, fun_si_iso2022jp_to_eucjp, NULL, fun_so_iso2022jp_to_eucjp
 };
 
 static int
-fun_so_eucjp_to_iso2022jp(rb_transcoding *t, const unsigned char *s, size_t l, unsigned char *o)
+fun_so_eucjp_to_iso2022jp(void *statep, const unsigned char *s, size_t l, unsigned char *o)
 {
+    unsigned char *sp = statep;
     unsigned char *output0 = o;
 
-    if (t->stateful[0] == 0) {
-        t->stateful[0] = 1; /* initialized flag */
-        t->stateful[1] = 1; /* G0 = ASCII */
-    }
-
-    if (l != t->stateful[1]) {
+    if (*sp != (l == 1 ? G0_ASCII : G0_JISX0208)) {
         if (l == 1) {
             *o++ = 0x1b;
             *o++ = '(';
             *o++ = 'B';
-            t->stateful[1] = 1; /* G0 = ASCII */
+            *sp = G0_ASCII;
         }
         else {
             *o++ = 0x1b;
             *o++ = '$';
             *o++ = 'B';
-            t->stateful[1] = 2; /* G0 = JIS X 0208 1983 */
+            *sp = G0_JISX0208; /* JIS X 0208 1983 */
         }
     }
 
@@ -115,27 +125,27 @@ fun_so_eucjp_to_iso2022jp(rb_transcoding *t, const unsigned char *s, size_t l, u
 }
 
 static int
-iso2022jp_reset_sequence_size(rb_transcoding *t)
+iso2022jp_reset_sequence_size(void *statep)
 {
-    if (t->stateful[1] == 2)
+    unsigned char *sp = statep;
+    if (*sp == G0_JISX0208)
         return 3;
     return 0;
 }
 
 static int
-finish_eucjp_to_iso2022jp(rb_transcoding *t, unsigned char *o)
+finish_eucjp_to_iso2022jp(void *statep, unsigned char *o)
 {
+    unsigned char *sp = statep;
     unsigned char *output0 = o;
 
-    if (t->stateful[0] == 0)
+    if (*sp == G0_ASCII)
         return 0;
 
-    if (t->stateful[1] != 1) {
-        *o++ = 0x1b;
-        *o++ = '(';
-        *o++ = 'B';
-        t->stateful[1] = 1;
-    }
+    *o++ = 0x1b;
+    *o++ = '(';
+    *o++ = 'B';
+    *sp = G0_ASCII;
 
     return o - output0;
 }
@@ -148,6 +158,7 @@ rb_EUC_JP_to_ISO_2022_JP = {
     3, /* max_input */
     5, /* max_output */
     stateful_encoder, /* stateful_type */
+    1, iso2022jp_init, iso2022jp_init, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, fun_so_eucjp_to_iso2022jp,
     finish_eucjp_to_iso2022jp,
     iso2022jp_reset_sequence_size, finish_eucjp_to_iso2022jp
diff --git a/enc/trans/japanese.trans b/enc/trans/japanese.trans
index 279957b972..64f38fbfc6 100644
--- a/enc/trans/japanese.trans
+++ b/enc/trans/japanese.trans
@@ -20,7 +20,7 @@
 <%= transcode_generated_code %>
 
 static int
-fun_so_eucjp2sjis(rb_transcoding *t, const unsigned char *s, size_t l, unsigned char* o)
+fun_so_eucjp2sjis(void *statep, const unsigned char *s, size_t l, unsigned char *o)
 {
     if (s[0] == 0x8e) {
         o[0] = s[1];
@@ -41,7 +41,7 @@ fun_so_eucjp2sjis(rb_transcoding *t, const unsigned char *s, size_t l, unsigned
 }
 
 static int
-fun_so_sjis2eucjp(rb_transcoding *t, const unsigned char *s, size_t l, unsigned char* o)
+fun_so_sjis2eucjp(void *statep, const unsigned char *s, size_t l, unsigned char *o)
 {
     if (l == 1) {
         o[0] = '\x8e';
@@ -49,7 +49,7 @@ fun_so_sjis2eucjp(rb_transcoding *t, const unsigned char *s, size_t l, unsigned
         return 2;
     }
     else {
-        int h, m, l;
+        int h, l;
         h = s[0];
         l = s[1];
         if (0xe0 <= h)
@@ -74,6 +74,7 @@ rb_eucjp2sjis = {
     3, /* max_input */
     2, /* max_output */
     stateless_converter, /* stateful_type */
+    0, NULL, NULL, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, fun_so_eucjp2sjis
 };
 
@@ -85,6 +86,7 @@ rb_sjis2eucjp = {
     2, /* max_input */
     2, /* max_output */
     stateless_converter, /* stateful_type */
+    0, NULL, NULL, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, fun_so_sjis2eucjp
 };
 
diff --git a/enc/trans/newline.trans b/enc/trans/newline.trans
index da8202eea4..7b10d368b1 100644
--- a/enc/trans/newline.trans
+++ b/enc/trans/newline.trans
@@ -21,33 +21,41 @@
 
 <%= transcode_generated_code %>
 
+#define NORMAL 0
+#define JUST_AFTER_CR 1
+
+static int
+universal_newline_init(void *statep)
+{
+    unsigned char *sp = statep;
+    *sp = NORMAL;
+    return 0;
+}
+
 static int
-fun_so_universal_newline(rb_transcoding* t, const unsigned char* s, size_t l, unsigned char* o)
+fun_so_universal_newline(void *statep, const unsigned char* s, size_t l, unsigned char* o)
 {
+    unsigned char *sp = statep;
     int len;
-    /*
-      t->stateful[0] == 0       : normal
-      t->stateful[0] == 1       : just after '\r'
-    */
     if (s[0] == '\n') {
-        if (t->stateful[0] == 0) {
+        if (*sp == NORMAL) {
             o[0] = '\n';
             len = 1;
         }
-        else {
+        else { /* JUST_AFTER_CR */
             len = 0;
         }
-        t->stateful[0] = 0;
+        *sp = NORMAL;
     }
     else if (s[0] == '\r') {
         o[0] = '\n';
         len = 1;
-        t->stateful[0] = 1;
+        *sp = JUST_AFTER_CR;
     }
     else {
         o[0] = s[0];
         len = 1;
-        t->stateful[0] = 0;
+        *sp = NORMAL;
     }
     return len;
 }
@@ -60,6 +68,7 @@ rb_universal_newline = {
     1, /* max_input */
     1, /* max_output */
     stateful_decoder, /* stateful_type */
+    1, universal_newline_init, universal_newline_init, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, fun_so_universal_newline
 };
 
@@ -71,6 +80,7 @@ rb_crlf_newline = {
     1, /* max_input */
     2, /* max_output */
     stateless_converter, /* stateful_type */
+    0, NULL, NULL, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, NULL
 };
 
@@ -82,6 +92,7 @@ rb_cr_newline = {
     1, /* max_input */
     1, /* max_output */
     stateless_converter, /* stateful_type */
+    0, NULL, NULL, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, NULL
 };
 
diff --git a/enc/trans/utf_16_32.trans b/enc/trans/utf_16_32.trans
index 57cd77dd77..9ffff341a9 100644
--- a/enc/trans/utf_16_32.trans
+++ b/enc/trans/utf_16_32.trans
@@ -38,7 +38,7 @@
 <%= transcode_generated_code %>
 
 static int
-fun_so_from_utf_16be(rb_transcoding* t, const unsigned char* s, size_t l, unsigned char* o)
+fun_so_from_utf_16be(void *statep, const unsigned char *s, size_t l, unsigned char *o)
 {
     if (!s[0] && s[1]<0x80) {
         o[0] = s[1];
@@ -66,7 +66,7 @@ fun_so_from_utf_16be(rb_transcoding* t, const unsigned char* s, size_t l, unsign
 }
 
 static int
-fun_so_to_utf_16be(rb_transcoding* t, const unsigned char* s, size_t l, unsigned char* o)
+fun_so_to_utf_16be(void *statep, const unsigned char *s, size_t l, unsigned char *o)
 {
     if (!(s[0]&0x80)) {
         o[0] = 0x00;
@@ -94,7 +94,7 @@ fun_so_to_utf_16be(rb_transcoding* t, const unsigned char* s, size_t l, unsigned
 }
 
 static int
-fun_so_from_utf_16le(rb_transcoding* t, const unsigned char* s, size_t l, unsigned char* o)
+fun_so_from_utf_16le(void *statep, const unsigned char *s, size_t l, unsigned char *o)
 {
     if (!s[1] && s[0]<0x80) {
         o[0] = s[0];
@@ -122,7 +122,7 @@ fun_so_from_utf_16le(rb_transcoding* t, const unsigned char* s, size_t l, unsign
 }
 
 static int
-fun_so_to_utf_16le(rb_transcoding* t, const unsigned char* s, size_t l, unsigned char* o)
+fun_so_to_utf_16le(void *statep, const unsigned char *s, size_t l, unsigned char *o)
 {
     if (!(s[0]&0x80)) {
         o[1] = 0x00;
@@ -150,7 +150,7 @@ fun_so_to_utf_16le(rb_transcoding* t, const unsigned char* s, size_t l, unsigned
 }
 
 static int
-fun_so_from_utf_32be(rb_transcoding* t, const unsigned char* s, size_t l, unsigned char* o)
+fun_so_from_utf_32be(void *statep, const unsigned char *s, size_t l, unsigned char *o)
 {
     if (!s[1]) {
         if (s[2]==0 && s[3]<0x80) {
@@ -179,7 +179,7 @@ fun_so_from_utf_32be(rb_transcoding* t, const unsigned char* s, size_t l, unsign
 }
 
 static int
-fun_so_to_utf_32be(rb_transcoding* t, const unsigned char* s, size_t l, unsigned char* o)
+fun_so_to_utf_32be(void *statep, const unsigned char *s, size_t l, unsigned char *o)
 {
     o[0] = 0;
     if (!(s[0]&0x80)) {
@@ -205,7 +205,7 @@ fun_so_to_utf_32be(rb_transcoding* t, const unsigned char* s, size_t l, unsigned
 }
 
 static int
-fun_so_from_utf_32le(rb_transcoding* t, const unsigned char* s, size_t l, unsigned char* o)
+fun_so_from_utf_32le(void *statep, const unsigned char *s, size_t l, unsigned char *o)
 {
     if (!s[2]) {
         if (s[1]==0 && s[0]<0x80) {
@@ -234,7 +234,7 @@ fun_so_from_utf_32le(rb_transcoding* t, const unsigned char* s, size_t l, unsign
 }
 
 static int
-fun_so_to_utf_32le(rb_transcoding* t, const unsigned char* s, size_t l, unsigned char* o)
+fun_so_to_utf_32le(void *statep, const unsigned char *s, size_t l, unsigned char *o)
 {
     o[3] = 0;
     if (!(s[0]&0x80)) {
@@ -267,6 +267,7 @@ rb_from_UTF_16BE = {
     4, /* max_input */
     4, /* max_output */
     stateless_converter, /* stateful_type */
+    0, NULL, NULL, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, fun_so_from_utf_16be
 };
 
@@ -278,6 +279,7 @@ rb_to_UTF_16BE = {
     4, /* max_input */
     4, /* max_output */
     stateless_converter, /* stateful_type */
+    0, NULL, NULL, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, fun_so_to_utf_16be
 };
 
@@ -289,6 +291,7 @@ rb_from_UTF_16LE = {
     4, /* max_input */
     4, /* max_output */
     stateless_converter, /* stateful_type */
+    0, NULL, NULL, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, fun_so_from_utf_16le
 };
 
@@ -300,6 +303,7 @@ rb_to_UTF_16LE = {
     4, /* max_input */
     4, /* max_output */
     stateless_converter, /* stateful_type */
+    0, NULL, NULL, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, fun_so_to_utf_16le
 };
 
@@ -311,6 +315,7 @@ rb_from_UTF_32BE = {
     4, /* max_input */
     4, /* max_output */
     stateless_converter, /* stateful_type */
+    0, NULL, NULL, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, fun_so_from_utf_32be
 };
 
@@ -322,6 +327,7 @@ rb_to_UTF_32BE = {
     4, /* max_input */
     4, /* max_output */
     stateless_converter, /* stateful_type */
+    0, NULL, NULL, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, fun_so_to_utf_32be
 };
 
@@ -333,6 +339,7 @@ rb_from_UTF_32LE = {
     4, /* max_input */
     4, /* max_output */
     stateless_converter, /* stateful_type */
+    0, NULL, NULL, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, fun_so_from_utf_32le
 };
 
@@ -344,6 +351,7 @@ rb_to_UTF_32LE = {
     4, /* max_input */
     4, /* max_output */
     stateless_converter, /* stateful_type */
+    0, NULL, NULL, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, fun_so_to_utf_32le
 };
 
diff --git a/tool/transcode-tblgen.rb b/tool/transcode-tblgen.rb
index 75b88b0083..207cb5118d 100644
--- a/tool/transcode-tblgen.rb
+++ b/tool/transcode-tblgen.rb
@@ -590,6 +590,7 @@ static const rb_transcoder
     #{max_input}, /* max_input */
     #{max_output}, /* max_output */
     stateless_converter, /* stateful_type */
+    0, NULL, NULL, /* state_size, state_init, state_fini */
     NULL, NULL, NULL, NULL,
     NULL, NULL, NULL
 };
diff --git a/transcode.c b/transcode.c
index aa89f12a8e..ca772ce844 100644
--- a/transcode.c
+++ b/transcode.c
@@ -544,22 +544,22 @@ transcode_restartable0(const unsigned char **in_pos, unsigned char **out_pos,
             SUSPEND_OBUF(19); *out_p++ = getBT3(next_info);
 	    continue;
 	  case FUNii:
-	    next_info = (VALUE)(*tr->func_ii)(tc, next_info);
+	    next_info = (VALUE)(*tr->func_ii)(TRANSCODING_STATE(tc), next_info);
 	    goto follow_info;
 	  case FUNsi:
             {
                 const unsigned char *char_start;
                 size_t char_len;
                 char_start = transcode_char_start(tc, *in_pos, inchar_start, in_p, &char_len);
-                next_info = (VALUE)(*tr->func_si)(tc, char_start, (size_t)char_len);
+                next_info = (VALUE)(*tr->func_si)(TRANSCODING_STATE(tc), char_start, (size_t)char_len);
                 goto follow_info;
             }
 	  case FUNio:
             SUSPEND_OBUF(13);
             if (tr->max_output <= out_stop - out_p)
-                out_p += (VALUE)(*tr->func_io)(tc, next_info, out_p);
+                out_p += (VALUE)(*tr->func_io)(TRANSCODING_STATE(tc), next_info, out_p);
             else {
-                writebuf_len = (VALUE)(*tr->func_io)(tc, next_info, TRANSCODING_WRITEBUF(tc));
+                writebuf_len = (VALUE)(*tr->func_io)(TRANSCODING_STATE(tc), next_info, TRANSCODING_WRITEBUF(tc));
                 writebuf_off = 0;
                 while (writebuf_off < writebuf_len) {
                     SUSPEND_OBUF(20);
@@ -574,11 +574,11 @@ transcode_restartable0(const unsigned char **in_pos, unsigned char **out_pos,
                 SUSPEND_OBUF(14);
                 if (tr->max_output <= out_stop - out_p) {
                     char_start = transcode_char_start(tc, *in_pos, inchar_start, in_p, &char_len);
-                    out_p += (VALUE)(*tr->func_so)(tc, char_start, (size_t)char_len, out_p);
+                    out_p += (VALUE)(*tr->func_so)(TRANSCODING_STATE(tc), char_start, (size_t)char_len, out_p);
                 }
                 else {
                     char_start = transcode_char_start(tc, *in_pos, inchar_start, in_p, &char_len);
-                    writebuf_len = (VALUE)(*tr->func_so)(tc, char_start, (size_t)char_len, TRANSCODING_WRITEBUF(tc));
+                    writebuf_len = (VALUE)(*tr->func_so)(TRANSCODING_STATE(tc), char_start, (size_t)char_len, TRANSCODING_WRITEBUF(tc));
                     writebuf_off = 0;
                     while (writebuf_off < writebuf_len) {
                         SUSPEND_OBUF(22);
@@ -632,10 +632,10 @@ transcode_restartable0(const unsigned char **in_pos, unsigned char **out_pos,
     if (tr->finish_func) {
         SUSPEND_OBUF(4);
         if (tr->max_output <= out_stop - out_p) {
-            out_p += tr->finish_func(tc, out_p);
+            out_p += tr->finish_func(TRANSCODING_STATE(tc), out_p);
         }
         else {
-            writebuf_len = tr->finish_func(tc, TRANSCODING_WRITEBUF(tc));
+            writebuf_len = tr->finish_func(TRANSCODING_STATE(tc), TRANSCODING_WRITEBUF(tc));
             writebuf_off = 0;
             while (writebuf_off < writebuf_len) {
                 SUSPEND_OBUF(23);
@@ -687,7 +687,11 @@ rb_transcoding_open_by_transcoder(const rb_transcoder *tr, int flags)
     tc = ALLOC(rb_transcoding);
     tc->transcoder = tr;
     tc->flags = flags;
-    memset(tc->stateful, 0, sizeof(tc->stateful));
+    if (TRANSCODING_STATE_EMBED_MAX < tr->state_size)
+        tc->state = xmalloc(tr->state_size);
+    if (tr->state_init_func) {
+        (tr->state_init_func)(TRANSCODING_STATE(tc)); /* xxx: check return value */
+    }
     tc->resume_position = 0;
     tc->recognized_len = 0;
     tc->readagain_len = 0;
@@ -718,6 +722,11 @@ static void
 rb_transcoding_close(rb_transcoding *tc)
 {
     const rb_transcoder *tr = tc->transcoder;
+    if (tr->state_fini_func) {
+        (tr->state_fini_func)(TRANSCODING_STATE(tc)); /* check return value? */
+    }
+    if (TRANSCODING_STATE_EMBED_MAX < tr->state_size)
+        xfree(tc->state);
     if (sizeof(tc->readbuf.ary) < tr->max_input)
         xfree(tc->readbuf.ptr);
     if (sizeof(tc->writebuf.ary) < tr->max_output)
diff --git a/transcode_data.h b/transcode_data.h
index 6081aec81d..a7f1db0c97 100644
--- a/transcode_data.h
+++ b/transcode_data.h
@@ -90,7 +90,7 @@ typedef struct rb_transcoding {
         unsigned char *ptr; /* length: max_output */
     } writebuf;
 
-    unsigned char stateful[256]; /* opaque data for stateful encoding */
+    void *state; /* opaque data for stateful encoding */
 } rb_transcoding;
 #define TRANSCODING_READBUF(tc) \
     ((tc)->transcoder->max_input <= sizeof((tc)->readbuf.ary) ? \
@@ -100,6 +100,11 @@ typedef struct rb_transcoding {
     ((tc)->transcoder->max_output <= sizeof((tc)->writebuf.ary) ? \
      (tc)->writebuf.ary : \
      (tc)->writebuf.ptr)
+#define TRANSCODING_STATE_EMBED_MAX sizeof(void *)
+#define TRANSCODING_STATE(tc) \
+    ((tc)->transcoder->state_size <= sizeof((tc)->state) ? \
+     (void *)&(tc)->state : \
+     (tc)->state)
 
 /* static structure, one per supported encoding pair */
 struct rb_transcoder {
@@ -115,13 +120,16 @@ struct rb_transcoder {
     int max_input;
     int max_output;
     rb_transcoder_stateful_type_t stateful_type;
-    VALUE (*func_ii)(rb_transcoding*, VALUE); /* info  -> info   */
-    VALUE (*func_si)(rb_transcoding*, const unsigned char*, size_t); /* start -> info   */
-    int (*func_io)(rb_transcoding*, VALUE, const unsigned char*); /* info  -> output */
-    int (*func_so)(rb_transcoding*, const unsigned char*, size_t, unsigned char*); /* start -> output */
-    int (*finish_func)(rb_transcoding*, unsigned char*); /* -> output */
-    int (*resetsize_func)(rb_transcoding*); /* -> len */
-    int (*resetstate_func)(rb_transcoding*, unsigned char*); /* -> output */
+    size_t state_size;
+    int (*state_init_func)(void*); /* 0:success !=0:failure(errno) */
+    int (*state_fini_func)(void*); /* 0:success !=0:failure(errno) */
+    VALUE (*func_ii)(void*, VALUE); /* info  -> info   */
+    VALUE (*func_si)(void*, const unsigned char*, size_t); /* start -> info   */
+    int (*func_io)(void*, VALUE, const unsigned char*); /* info  -> output */
+    int (*func_so)(void*, const unsigned char*, size_t, unsigned char*); /* start -> output */
+    int (*finish_func)(void*, unsigned char*); /* -> output */
+    int (*resetsize_func)(void*); /* -> len */
+    int (*resetstate_func)(void*, unsigned char*); /* -> output */
 };
 
 void rb_declare_transcoder(const char *enc1, const char *enc2, const char *lib);