Fix streaming unpacking for splitted packed data

perl/t/10_splitted_bytes.t

@@ -20,8 +20,6 @@ my $input = [
 my $packed = Data::MessagePack->pack($input);
 
 foreach my $size(1 .. 16) {
-    local $TODO = "Splitted byte streaming is not yet supported (bufer size: $size)";
-
     my $up = Data::MessagePack::Unpacker->new();
 
     open my $stream, '<:bytes :scalar', \$packed;
@@ -29,7 +27,7 @@ foreach my $size(1 .. 16) {
     my $buff;
     my $done = 0;
     while( read($stream, $buff, $size) ) {
-        #note "buff: ", join " ", map { unpack 'H2', $_ } split //, $buff;
+        note "buff: ", join " ", map { unpack 'H2', $_ } split //, $buff;
 
         $done = $up->execute($buff);
     }

perl/t/16_unpacker_for_larges.t

@@ -0,0 +1,22 @@
+use strict;
+use Test::More;
+use Data::MessagePack;
+
+foreach my $data("abc") {
+    my $packed = Data::MessagePack->pack($data);
+
+    my $unpacker = Data::MessagePack::Unpacker->new;
+    note "buff: ", join " ", map { unpack 'H2', $_ } split //, $packed;
+
+    my $offset = 0;
+    foreach my $byte(split //, $packed) {
+        note "offset: $offset";
+        $offset += $unpacker->execute($byte);
+    }
+
+    ok $unpacker->is_finished, 'finished';
+    is_deeply $unpacker->data, $data, 'data';
+}
+
+done_testing;
+

perl/xs-src/unpack.c

@@ -9,11 +9,13 @@ typedef struct {
 } my_cxt_t;
 START_MY_CXT
 
+// context data for execute_template()
 typedef struct {
     bool finished;
-    bool incremented;
     bool utf8;
+    SV*  buffer;
 } unpack_user;
+#define UNPACK_USER_INIT { false, false, NULL }
 
 #include "msgpack/unpack_define.h"
 
@@ -301,7 +303,7 @@ XS(xs_unpack) {
     msgpack_unpack_t mp;
     template_init(&mp);
 
-    unpack_user const u = {false, false, false};
+    unpack_user const u = UNPACK_USER_INIT;
     mp.user = u;
 
     size_t from = 0;
@@ -326,14 +328,6 @@ XS(xs_unpack) {
 /* ------------------------------ stream -- */
 /* http://twitter.com/frsyuki/status/13249304748 */
 
-STATIC_INLINE void _reset(SV* const self) {
-    dTHX;
-	unpack_user const u = {false, false, false};
-
-	UNPACKER(self, mp);
-	template_init(mp);
-	mp->user = u;
-}
 
 XS(xs_unpacker_new) {
     dXSARGS;
@@ -345,9 +339,14 @@ XS(xs_unpacker_new) {
     msgpack_unpack_t *mp;
 
     Newxz(mp, 1, msgpack_unpack_t);
+    template_init(mp);
+    unpack_user const u = UNPACK_USER_INIT;
+    mp->user = u;
+
+    mp->user.buffer = newSV(80);
+    sv_setpvs(mp->user.buffer, "");
 
     sv_setref_pv(self, "Data::MessagePack::Unpacker", mp);
-    _reset(self);
 
     ST(0) = self;
     XSRETURN(1);
@@ -378,21 +377,44 @@ _execute_impl(SV* const self, SV* const data, UV const offset, UV const limit) {
     dTHX;
 
     if(offset >= limit) {
-        Perl_croak(aTHX_ "offset (%"UVuf") is bigger than data buffer size (%"UVuf")",
+        Perl_croak(aTHX_
+            "offset (%"UVuf") is bigger than data buffer size (%"UVuf")",
             offset, limit);
     }
 
     UNPACKER(self, mp);
 
     size_t from = offset;
-    const char* const dptr = SvPV_nolen_const(data);
+    const char* dptr = SvPV_nolen_const(data);
+    STRLEN      dlen = limit;
 
-    int const ret = template_execute(mp, dptr, limit, &from);
+    if(SvCUR(mp->user.buffer) != 0) {
+        sv_catpvn(mp->user.buffer, dptr, dlen);
+        dptr = SvPV_const(mp->user.buffer, dlen);
+        from = 0;
+    }
+
+    int const ret = template_execute(mp, dptr, dlen, &from);
+    // ret <  0 : error
+    // ret == 0 : insufficient
+    // ret >  0 : success
 
     if(ret < 0) {
-        Perl_croak(aTHX_ "Data::MessagePack::Unpacker: parse error while executing");
+        Perl_croak(aTHX_
+            "Data::MessagePack::Unpacker: parse error while executing");
     }
+
     mp->user.finished = (ret > 0) ? true : false;
+    if(!mp->user.finished) {
+        template_init(mp); // reset the state
+        sv_setpvn(mp->user.buffer, dptr, dlen);
+        from = 0;
+    }
+    else {
+        sv_setpvs(mp->user.buffer, "");
+    }
+    //warn(">> (%d) dlen=%d, from=%d, rest=%d",
+    //    (int)ret, (int)dlen, (int)from, dlen - from);
     return from;
 }
 
@@ -464,12 +486,12 @@ XS(xs_unpacker_reset) {
     }
 
     UNPACKER(ST(0), mp);
-    bool const utf8 = mp->user.utf8; // save
 
     SV* const data = template_data(mp);
     SvREFCNT_dec(data);
-    _reset(ST(0));
+
-    mp->user.utf8 = utf8;
+    template_init(mp);
+    sv_setpvs(mp->user.buffer, "");
 
     XSRETURN(0);
 }
@@ -484,6 +506,7 @@ XS(xs_unpacker_destroy) {
 
     SV* const data = template_data(mp);
     SvREFCNT_dec(data);
+    SvREFCNT_dec(mp->user.buffer);
     Safefree(mp);
 
     XSRETURN(0);