Merge branch 'master' into canonicalize-pr

c++/CMakeLists.txt

@@ -109,6 +109,9 @@ if(NOT MSVC)  # Don't install pkg-config files when building with MSVC
 
     configure_file(capnp-rpc.pc.in "${CMAKE_CURRENT_BINARY_DIR}/capnp-rpc.pc" @ONLY)
     install(FILES "${CMAKE_CURRENT_BINARY_DIR}/capnp-rpc.pc" DESTINATION "${LIB_INSTALL_DIR}/pkgconfig")
+
+    configure_file(capnp-json.pc.in "${CMAKE_CURRENT_BINARY_DIR}/capnp-json.pc" @ONLY)
+    install(FILES "${CMAKE_CURRENT_BINARY_DIR}/capnp-json.pc" DESTINATION "${LIB_INSTALL_DIR}/pkgconfig")
   endif()
 
   unset(STDLIB_FLAG)

c++/Makefile.am

@@ -74,7 +74,8 @@ public_capnpc_inputs =                                         \
   src/capnp/schema.capnp                                       \
   src/capnp/rpc.capnp                                          \
   src/capnp/rpc-twoparty.capnp                                 \
-  src/capnp/persistent.capnp
+  src/capnp/persistent.capnp                                   \
+  src/capnp/compat/json.capnp
 
 capnpc_inputs =                                                \
   $(public_capnpc_inputs)                                      \
@@ -92,12 +93,15 @@ capnpc_outputs =                                               \
   src/capnp/rpc-twoparty.capnp.h                               \
   src/capnp/persistent.capnp.c++                               \
   src/capnp/persistent.capnp.h                                 \
+  src/capnp/compat/json.capnp.h                                \
+  src/capnp/compat/json.capnp.c++                              \
   src/capnp/compiler/lexer.capnp.c++                           \
   src/capnp/compiler/lexer.capnp.h                             \
   src/capnp/compiler/grammar.capnp.c++                         \
   src/capnp/compiler/grammar.capnp.h
 
 includecapnpdir = $(includedir)/capnp
+includecapnpcompatdir = $(includecapnpdir)/compat
 includekjdir = $(includedir)/kj
 includekjparsedir = $(includekjdir)/parse
 includekjstddir = $(includekjdir)/std
@@ -183,10 +187,14 @@ includecapnp_HEADERS =                                         \
   src/capnp/persistent.capnp.h                                 \
   src/capnp/ez-rpc.h
 
+includecapnpcompat_HEADERS =                                   \
+  src/capnp/compat/json.h                                      \
+  src/capnp/compat/json.capnp.h
+
 if LITE_MODE
 lib_LTLIBRARIES = libkj.la libkj-test.la libcapnp.la
 else
-lib_LTLIBRARIES = libkj.la libkj-test.la libkj-async.la libcapnp.la libcapnp-rpc.la libcapnpc.la
+lib_LTLIBRARIES = libkj.la libkj-test.la libkj-async.la libcapnp.la libcapnp-rpc.la libcapnp-json.la libcapnpc.la
 endif
 
 # Don't include security release in soname -- we want to replace old binaries
@@ -266,6 +274,12 @@ libcapnp_rpc_la_SOURCES=                                       \
   src/capnp/persistent.capnp.c++                               \
   src/capnp/ez-rpc.c++
 
+libcapnp_json_la_LIBADD = libcapnp.la libkj-async.la libkj.la $(PTHREAD_LIBS)
+libcapnp_json_la_LDFLAGS = -release $(SO_VERSION) -no-undefined
+libcapnp_json_la_SOURCES=                                      \
+  src/capnp/compat/json.c++                                    \
+  src/capnp/compat/json.capnp.c++
+
 libcapnpc_la_LIBADD = libcapnp.la libkj.la $(PTHREAD_LIBS)
 libcapnpc_la_LDFLAGS = -release $(SO_VERSION) -no-undefined
 libcapnpc_la_SOURCES=                                          \
@@ -388,9 +402,16 @@ heavy_tests =                                                  \
   src/capnp/rpc-test.c++                                       \
   src/capnp/rpc-twoparty-test.c++                              \
   src/capnp/ez-rpc-test.c++                                    \
+  src/capnp/compat/json-test.c++                               \
   src/capnp/compiler/lexer-test.c++                            \
   src/capnp/compiler/md5-test.c++
-capnp_test_LDADD = libcapnpc.la libcapnp-rpc.la libcapnp.la libkj-async.la libkj-test.la libkj.la
+capnp_test_LDADD = libcapnpc.la                                \
+  libcapnp-rpc.la                                              \
+  libcapnp-json.la                                             \
+  libcapnp.la                                                  \
+  libkj-async.la                                               \
+  libkj-test.la                                                \
+  libkj.la
 
 endif !LITE_MODE
 

c++/capnp-json.pc.in

+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: Cap'n Proto JSON
+Description: JSON encoder and decoder for Cap'n Proto objects
+Version: @VERSION@
+Libs: -L${libdir} -lcapnp-json
+Requires: capnp = @VERSION@ kj-async = @VERSION@
+Cflags: -I${includedir}

c++/cmake/FindCapnProto.cmake

@@ -134,6 +134,7 @@ endfunction()
 find_package(PkgConfig QUIET)
 pkg_check_modules(PKGCONFIG_CAPNP capnp)
 pkg_check_modules(PKGCONFIG_CAPNP_RPC capnp-rpc QUIET)
+pkg_check_modules(PKGCONFIG_CAPNP_JSON capnp-json QUIET)
 
 find_library(CAPNP_LIB_KJ kj
   HINTS "${PKGCONFIG_CAPNP_LIBDIR}" ${PKGCONFIG_CAPNP_LIBRARY_DIRS}
@@ -147,12 +148,16 @@ find_library(CAPNP_LIB_CAPNP capnp
 find_library(CAPNP_LIB_CAPNP-RPC capnp-rpc
   HINTS "${PKGCONFIG_CAPNP_RPC_LIBDIR}" ${PKGCONFIG_CAPNP_RPC_LIBRARY_DIRS}
 )
-mark_as_advanced(CAPNP_LIB_KJ CAPNP_LIB_KJ-ASYNC CAPNP_LIB_CAPNP CAPNP_LIB_CAPNP-RPC)
+find_library(CAPNP_LIB_CAPNP-JSON capnp-json
+  HINTS "${PKGCONFIG_CAPNP_JSON_LIBDIR}" ${PKGCONFIG_CAPNP_JSON_LIBRARY_DIRS}
+)
+mark_as_advanced(CAPNP_LIB_KJ CAPNP_LIB_KJ-ASYNC CAPNP_LIB_CAPNP CAPNP_LIB_CAPNP-RPC CAPNP_LIB_CAPNP-JSON)
 set(CAPNP_LIBRARIES_LITE
   ${CAPNP_LIB_CAPNP}
   ${CAPNP_LIB_KJ}
 )
 set(CAPNP_LIBRARIES
+  ${CAPNP_LIB_CAPNP-JSON}
   ${CAPNP_LIB_CAPNP-RPC}
   ${CAPNP_LIB_CAPNP}
   ${CAPNP_LIB_KJ-ASYNC}

c++/configure.ac

@@ -101,5 +101,5 @@ AC_SUBST([STDLIB_FLAG])
 LIBS="$PTHREAD_LIBS $LIBS"
 CXXFLAGS="$CXXFLAGS $PTHREAD_CFLAGS"
 
-AC_CONFIG_FILES([Makefile capnp.pc capnp-rpc.pc kj.pc kj-async.pc])
+AC_CONFIG_FILES([Makefile capnp.pc capnp-rpc.pc capnp-json.pc kj.pc kj-async.pc])
 AC_OUTPUT

c++/regenerate-bootstraps.sh

@@ -7,4 +7,5 @@ export PATH=$PWD/bin:$PWD:$PATH
 capnp compile -Isrc --no-standard-import --src-prefix=src -oc++:src \
     src/capnp/c++.capnp src/capnp/schema.capnp \
     src/capnp/compiler/lexer.capnp src/capnp/compiler/grammar.capnp \
-    src/capnp/rpc.capnp src/capnp/rpc-twoparty.capnp src/capnp/persistent.capnp
+    src/capnp/rpc.capnp src/capnp/rpc-twoparty.capnp src/capnp/persistent.capnp \
+    src/capnp/compat/json.capnp

c++/src/capnp/CMakeLists.txt

@@ -94,6 +94,26 @@ if(NOT CAPNP_LITE)
   install(FILES ${capnp-rpc_headers} ${capnp-rpc_schemas} DESTINATION "${INCLUDE_INSTALL_DIR}/capnp")
 endif()
 
+# capnp-json ========================================================================
+
+set(capnp-json_sources
+  compat/json.c++
+  compat/json.capnp.c++
+)
+set(capnp-json_headers
+  compat/json.h
+  compat/json.capnp.h
+)
+set(capnp-json_schemas
+  compat/json.capnp
+)
+if(NOT CAPNP_LITE)
+  add_library(capnp-json ${capnp-json_sources})
+  target_link_libraries(capnp-json capnp kj-async kj)
+  install(TARGETS capnp-json ARCHIVE DESTINATION "${LIB_INSTALL_DIR}")
+  install(FILES ${capnp-json_headers} ${capnp-json_schemas} DESTINATION "${INCLUDE_INSTALL_DIR}/capnp/compat")
+endif()
+
 # Tools/Compilers ==============================================================
 
 set(capnpc_sources
@@ -185,7 +205,7 @@ if(BUILD_TESTING)
   if(CAPNP_LITE)
     set(test_libraries capnp kj-test kj)
   else()
-    set(test_libraries capnp-rpc capnp capnpc kj-async kj-test kj)
+    set(test_libraries capnp-json capnp-rpc capnp capnpc kj-async kj-test kj)
   endif()
 
   add_executable(capnp-tests
@@ -228,6 +248,7 @@ if(BUILD_TESTING)
       compiler/lexer-test.c++
       compiler/md5-test.c++
       test-util.c++
+      compat/json-test.c++
       ${test_capnp_cpp_files}
       ${test_capnp_h_files}
     )

c++/src/capnp/capnpc.ekam-rule

@@ -37,7 +37,8 @@ case "$INPUT" in
     *capnp/rpc-twoparty.capnp | \
     *capnp/persistent.capnp | \
     *capnp/compiler/lexer.capnp | \
-    *capnp/compiler/grammar.capnp )
+    *capnp/compiler/grammar.capnp | \
+    *capnp/compat/json.capnp )
         exit 0
         ;;
 esac

c++/src/capnp/compiler/capnp-test.sh

@@ -41,11 +41,13 @@ TESTDATA=`dirname "$0"`/../testdata
 $CAPNP encode $SCHEMA TestAllTypes < $TESTDATA/short.txt | cmp $TESTDATA/binary - || fail encode
 $CAPNP encode --flat $SCHEMA TestAllTypes < $TESTDATA/short.txt | cmp $TESTDATA/flat - || fail encode flat
 $CAPNP encode --packed $SCHEMA TestAllTypes < $TESTDATA/short.txt | cmp $TESTDATA/packed - || fail encode packed
+$CAPNP encode --packed --flat $SCHEMA TestAllTypes < $TESTDATA/short.txt | cmp $TESTDATA/packedflat - || fail encode packedflat
 $CAPNP encode $SCHEMA TestAllTypes < $TESTDATA/pretty.txt | cmp $TESTDATA/binary - || fail parse pretty
 
 $CAPNP decode $SCHEMA TestAllTypes < $TESTDATA/binary | cmp $TESTDATA/pretty.txt - || fail decode
 $CAPNP decode --flat $SCHEMA TestAllTypes < $TESTDATA/flat | cmp $TESTDATA/pretty.txt - || fail decode flat
 $CAPNP decode --packed $SCHEMA TestAllTypes < $TESTDATA/packed | cmp $TESTDATA/pretty.txt - || fail decode packed
+$CAPNP decode --packed --flat $SCHEMA TestAllTypes < $TESTDATA/packedflat | cmp $TESTDATA/pretty.txt - || fail decode packedflat
 $CAPNP decode --short $SCHEMA TestAllTypes < $TESTDATA/binary | cmp $TESTDATA/short.txt - || fail decode short
 
 $CAPNP decode $SCHEMA TestAllTypes < $TESTDATA/segmented | cmp $TESTDATA/pretty.txt - || fail decode segmented

c++/src/capnp/layout.c++

@@ -1662,6 +1662,8 @@ struct WireHelpers {
       return { segment, ptr };
     } else {
       // List of structs.
+      KJ_DASSERT(value.structDataSize % BITS_PER_WORD == 0 * BITS);
+
       WordCount declDataSize = roundBitsUpToWords(value.structDataSize);
       WirePointerCount declPointerCount = value.structPointerCount;
 

c++/src/capnp/layout.h

@@ -667,7 +667,8 @@ class ListBuilder: public kj::DisallowConstCopy {
 public:
   inline explicit ListBuilder(ElementSize elementSize)
       : segment(nullptr), capTable(nullptr), ptr(nullptr), elementCount(0 * ELEMENTS),
-        step(0 * BITS / ELEMENTS), elementSize(elementSize) {}
+        step(0 * BITS / ELEMENTS), elementSize(elementSize), structDataSize(0 * BITS),
+        structPointerCount(0 * POINTERS) {}
 
   MSVC_DEFAULT_ASSIGNMENT_WORKAROUND(, ListBuilder)
 

c++/src/capnp/serialize-packed-test.c++

@@ -39,6 +39,11 @@ public:
   ~TestPipe() {}
 
   const std::string& getData() { return data; }
+
+  kj::ArrayPtr<const byte> getArray() {
+    return kj::arrayPtr(reinterpret_cast<const byte*>(data.data()), data.size());
+  }
+
   void resetRead(size_t preferredReadSize = kj::maxValue) {
     readPos = 0;
     this->preferredReadSize = preferredReadSize;
@@ -84,6 +89,8 @@ private:
 void expectPacksTo(kj::ArrayPtr<const byte> unpacked, kj::ArrayPtr<const byte> packed) {
   TestPipe pipe;
 
+  EXPECT_EQ(unpacked.size(), computeUnpackedSizeInWords(packed) * sizeof(word));
+
   // -----------------------------------------------------------------
   // write
 
@@ -244,6 +251,8 @@ TEST(Packed, RoundTrip) {
   TestPipe pipe;
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   checkTestMessage(reader.getRoot<TestAllTypes>());
 }
@@ -255,6 +264,8 @@ TEST(Packed, RoundTripScratchSpace) {
   TestPipe pipe;
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   word scratch[1024];
   PackedMessageReader reader(pipe, ReaderOptions(), kj::ArrayPtr<word>(scratch, 1024));
   checkTestMessage(reader.getRoot<TestAllTypes>());
@@ -267,6 +278,8 @@ TEST(Packed, RoundTripLazy) {
   TestPipe pipe(1);
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   checkTestMessage(reader.getRoot<TestAllTypes>());
 }
@@ -278,6 +291,8 @@ TEST(Packed, RoundTripOddSegmentCount) {
   TestPipe pipe;
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   checkTestMessage(reader.getRoot<TestAllTypes>());
 }
@@ -289,6 +304,8 @@ TEST(Packed, RoundTripOddSegmentCountLazy) {
   TestPipe pipe(1);
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   checkTestMessage(reader.getRoot<TestAllTypes>());
 }
@@ -300,6 +317,8 @@ TEST(Packed, RoundTripEvenSegmentCount) {
   TestPipe pipe;
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   checkTestMessage(reader.getRoot<TestAllTypes>());
 }
@@ -311,6 +330,8 @@ TEST(Packed, RoundTripEvenSegmentCountLazy) {
   TestPipe pipe(1);
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   checkTestMessage(reader.getRoot<TestAllTypes>());
 }
@@ -326,6 +347,9 @@ TEST(Packed, RoundTripTwoMessages) {
   writePackedMessage(pipe, builder);
   writePackedMessage(pipe, builder2);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder) + computeSerializedSizeInWords(builder2),
+            computeUnpackedSizeInWords(pipe.getArray()));
+
   {
     PackedMessageReader reader(pipe);
     checkTestMessage(reader.getRoot<TestAllTypes>());
@@ -346,6 +370,8 @@ TEST(Packed, RoundTripAllZero) {
   TestPipe pipe;
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   checkTestMessageAllZero(reader.getRoot<TestAllTypes>());
 
@@ -362,6 +388,8 @@ TEST(Packed, RoundTripAllZeroScratchSpace) {
   TestPipe pipe;
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   word scratch[1024];
   PackedMessageReader reader(pipe, ReaderOptions(), kj::ArrayPtr<word>(scratch, 1024));
   checkTestMessageAllZero(reader.getRoot<TestAllTypes>());
@@ -374,6 +402,8 @@ TEST(Packed, RoundTripAllZeroLazy) {
   TestPipe pipe(1);
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   checkTestMessageAllZero(reader.getRoot<TestAllTypes>());
 }
@@ -385,6 +415,8 @@ TEST(Packed, RoundTripAllZeroOddSegmentCount) {
   TestPipe pipe;
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   checkTestMessageAllZero(reader.getRoot<TestAllTypes>());
 }
@@ -396,6 +428,8 @@ TEST(Packed, RoundTripAllZeroOddSegmentCountLazy) {
   TestPipe pipe(1);
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   checkTestMessageAllZero(reader.getRoot<TestAllTypes>());
 }
@@ -407,6 +441,8 @@ TEST(Packed, RoundTripAllZeroEvenSegmentCount) {
   TestPipe pipe;
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   checkTestMessageAllZero(reader.getRoot<TestAllTypes>());
 }
@@ -418,6 +454,8 @@ TEST(Packed, RoundTripAllZeroEvenSegmentCountLazy) {
   TestPipe pipe(1);
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   checkTestMessageAllZero(reader.getRoot<TestAllTypes>());
 }
@@ -434,6 +472,8 @@ TEST(Packed, RoundTripHugeString) {
   TestPipe pipe;
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   EXPECT_TRUE(reader.getRoot<TestAllTypes>().getTextField() == huge);
 }
@@ -448,6 +488,8 @@ TEST(Packed, RoundTripHugeStringScratchSpace) {
   TestPipe pipe;
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   word scratch[1024];
   PackedMessageReader reader(pipe, ReaderOptions(), kj::ArrayPtr<word>(scratch, 1024));
   EXPECT_TRUE(reader.getRoot<TestAllTypes>().getTextField() == huge);
@@ -463,6 +505,8 @@ TEST(Packed, RoundTripHugeStringLazy) {
   TestPipe pipe(1);
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   EXPECT_TRUE(reader.getRoot<TestAllTypes>().getTextField() == huge);
 }
@@ -477,6 +521,8 @@ TEST(Packed, RoundTripHugeStringOddSegmentCount) {
   TestPipe pipe;
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   EXPECT_TRUE(reader.getRoot<TestAllTypes>().getTextField() == huge);
 }
@@ -491,6 +537,8 @@ TEST(Packed, RoundTripHugeStringOddSegmentCountLazy) {
   TestPipe pipe(1);
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   EXPECT_TRUE(reader.getRoot<TestAllTypes>().getTextField() == huge);
 }
@@ -505,6 +553,8 @@ TEST(Packed, RoundTripHugeStringEvenSegmentCount) {
   TestPipe pipe;
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   EXPECT_TRUE(reader.getRoot<TestAllTypes>().getTextField() == huge);
 }
@@ -519,6 +569,8 @@ TEST(Packed, RoundTripHugeStringEvenSegmentCountLazy) {
   TestPipe pipe(1);
   writePackedMessage(pipe, builder);
 
+  EXPECT_EQ(computeSerializedSizeInWords(builder), computeUnpackedSizeInWords(pipe.getArray()));
+
   PackedMessageReader reader(pipe);
   EXPECT_TRUE(reader.getRoot<TestAllTypes>().getTextField() == huge);
 }

c++/src/capnp/serialize-packed.c++

@@ -43,7 +43,7 @@ size_t PackedInputStream::tryRead(void* dst, size_t minBytes, size_t maxBytes) {
   uint8_t* const outEnd = reinterpret_cast<uint8_t*>(dst) + maxBytes;
   uint8_t* const outMin = reinterpret_cast<uint8_t*>(dst) + minBytes;
 
-  kj::ArrayPtr<const byte> buffer = inner.getReadBuffer();
+  kj::ArrayPtr<const byte> buffer = inner.tryGetReadBuffer();
   if (buffer.size() == 0) {
     return 0;
   }
@@ -476,4 +476,32 @@ void writePackedMessageToFd(int fd, kj::ArrayPtr<const kj::ArrayPtr<const word>>
   writePackedMessage(output, segments);
 }
 
+size_t computeUnpackedSizeInWords(kj::ArrayPtr<const byte> packedBytes) {
+  const byte* ptr = packedBytes.begin();
+  const byte* end = packedBytes.end();
+
+  size_t total = 0;
+  while (ptr < end) {
+    uint tag = *ptr;
+    size_t count = __builtin_popcount(tag);
+    total += 1;
+    KJ_REQUIRE(end - ptr >= count, "invalid packed data");
+    ptr += count + 1;
+
+    if (tag == 0) {
+      KJ_REQUIRE(ptr < end, "invalid packed data");
+      total += *ptr++;
+    } else if (tag == 0xff) {
+      KJ_REQUIRE(ptr < end, "invalid packed data");
+      size_t words = *ptr++;
+      total += words;
+      size_t bytes = words * sizeof(word);
+      KJ_REQUIRE(end - ptr >= bytes, "invalid packed data");
+      ptr += bytes;
+    }
+  }
+
+  return total;
+}
+
 }  // namespace capnp

c++/src/capnp/serialize-packed.h

@@ -106,6 +106,10 @@ void writePackedMessageToFd(int fd, MessageBuilder& builder);
 void writePackedMessageToFd(int fd, kj::ArrayPtr<const kj::ArrayPtr<const word>> segments);
 // Write a single packed message to the file descriptor.
 
+size_t computeUnpackedSizeInWords(kj::ArrayPtr<const byte> packedBytes);
+// Computes the number of words to which the given packed bytes will unpack. Not intended for use
+// in performance-sensitive situations.
+
 // =======================================================================================
 // inline stuff
 

c++/src/kj/vector.h

@@ -103,6 +103,22 @@ public:
     }
   }
 
+  inline void operator=(decltype(nullptr)) {
+    builder = nullptr;
+  }
+
+  inline void clear() {
+    while (builder.size() > 0) {
+      builder.removeLast();
+    }
+  }
+
+  inline void truncate(size_t size) {
+    while (builder.size() > size) {
+      builder.removeLast();
+    }
+  }
+
 private:
   ArrayBuilder<T> builder;
 

doc/otherlang.md

@@ -22,7 +22,7 @@ project's documentation for details.
 
 ##### Serialization only
 
-* [C](https://github.com/jmckaskill/c-capnproto) by [@jmckaskill](https://github.com/jmckaskill)
+* [C](https://github.com/opensourcerouting/c-capnproto) by [OpenSourceRouting](https://www.opensourcerouting.org/) / [@eqvinox](https://github.com/eqvinox) (originally by [@jmckaskill](https://github.com/jmckaskill))
 * [C#](https://github.com/mgravell/capnproto-net) by [@mgravell](https://github.com/mgravell)
 * [Go](https://github.com/glycerine/go-capnproto) by [@glycerine](https://github.com/glycerine) (originally by [@jmckaskill](https://github.com/jmckaskill))
 * [Java](https://github.com/dwrensha/capnproto-java/) by [@dwrensha](https://github.com/dwrensha)
@@ -41,8 +41,8 @@ new languages.
 * [Common Test Framework](https://github.com/kaos/capnp_test) by [@kaos](https://github.com/kaos)
 * [Sublime Syntax Highlighting](https://github.com/joshuawarner32/capnproto-sublime) by
   [@joshuawarner32](https://github.com/joshuawarner32)
-* [Vim Syntax Highlighting](https://github.com/cstrahan/vim-capnp) by
-  [@cstrahan](https://github.com/cstrahan)
+* [Vim Syntax Highlighting](https://github.com/peter-edge/vim-capnp) by [@peter-edge](https://github.com/peter-edge)
+  (originally by [@cstrahan](https://github.com/cstrahan))
 * [Wireshark Dissector Plugin](https://github.com/kaos/wireshark-plugins) by [@kaos](https://github.com/kaos)
 
 ## Contribute Your Own!