[OTS] Integrate WOFF 2.0 algorithm into OTS

src/ots.cc

Index: src/ots.cc
===================================================================
--- src/ots.cc	(revision 99)
+++ src/ots.cc	(working copy)
@@ -14,12 +14,15 @@
 #include <map>
 #include <vector>
 
+#include "woff2.h"
+
 // The OpenType Font File
 // http://www.microsoft.com/typography/otspec/cmap.htm
 
 namespace {
 
 bool g_debug_output = true;
+bool g_enable_woff2 = false;
 
 struct OpenTypeTable {
   uint32_t tag;
@@ -402,6 +405,21 @@
   return ProcessGeneric(header, woff_tag, output, data, length, tables, file);
 }
 
+bool ProcessWOFF2(ots::OpenTypeFile *header,
+                  ots::OTSStream *output, const uint8_t *data, size_t length) {
+  size_t decompressed_size = ots::ComputeWOFF2FinalSize(data, length);
+  if (decompressed_size == 0) {
+    return OTS_FAILURE();
+  }
+
+  std::vector<uint8_t> decompressed_buffer(decompressed_size);

[Yusuke Sato, 2013/04/17 18:38:46]

* Do we have to zero-fill the buffer?
* Please define the max decompressed size and return with OTS_FAILURE() when
|decompressed_size| exceeds that. With the current code, I guess drive-by web
can easily crash the renderer by oom.

[Kunihiko Sakamoto, 2013/04/23 06:36:26]

Done.
Good catch, thanks.
I set the limit to 30MB, that is somewhat stricter than other formats where sum
of decompressed tables must be <=30MB.

[Yusuke Sato, 2013/05/07 06:11:27]

std::vector<uint8_t> decompressed_buffer(decompressed_size, 0); and
std::vector<uint8_t> decompressed_buffer(decompressed_size); are the same,
aren't they?

Sorry, I should've been more clear. Please do *NOT* zero-clear the buffer unless
it's really necessary. For example, scoped array and new unit8_t[] may suffice.
 

[Kunihiko Sakamoto, 2013/05/07 10:17:23]

Oh, got it.
We should zero clear this buffer, because ConvertWOFF2ToTTF() does not overwrite
padding-bytes.

+  if (!ots::ConvertWOFF2ToTTF(&decompressed_buffer[0], decompressed_size,
+                              data, length)) {
+    return OTS_FAILURE();
+  }
+  return ProcessTTF(header, output, &decompressed_buffer[0], decompressed_size);
+}
+
 bool ProcessGeneric(ots::OpenTypeFile *header, uint32_t signature,
                     ots::OTSStream *output,
                     const uint8_t *data, size_t length,
@@ -683,6 +701,10 @@
   g_debug_output = false;
 }
 
+void EnableWOFF2() {
+  g_enable_woff2 = true;
+}
+
 bool Process(OTSStream *output, const uint8_t *data, size_t length) {
   OpenTypeFile header;
   if (length < 4) {
@@ -692,6 +714,10 @@
   bool result;
   if (data[0] == 'w' && data[1] == 'O' && data[2] == 'F' && data[3] == 'F') {
     result = ProcessWOFF(&header, output, data, length);
+  } else if (g_enable_woff2 &&
+             data[0] == 'w' && data[1] == 'O' && data[2] == 'F' &&
+             data[3] == '2') {
+    result = ProcessWOFF2(&header, output, data, length);
   } else {
     result = ProcessTTF(&header, output, data, length);
   }