1 files changed, 256 insertions, 0 deletions
diff --git a/mfbt/tests/TestBufferList.cpp b/mfbt/tests/TestBufferList.cpp
new file mode 100644
index 0000000000..cccaac021b
--- /dev/null
+++ b/mfbt/tests/TestBufferList.cpp
@@ -0,0 +1,256 @@
+/* -*- Mode: C++; tab-width: 9; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// This is included first to ensure it doesn't implicitly depend on anything
+// else.
+#include "mozilla/BufferList.h"
+
+// It would be nice if we could use the InfallibleAllocPolicy from mozalloc,
+// but MFBT cannot use mozalloc.
+class InfallibleAllocPolicy
+{
+public:
+  template <typename T>
+  T* pod_malloc(size_t aNumElems)
+  {
+    if (aNumElems & mozilla::tl::MulOverflowMask<sizeof(T)>::value) {
+      MOZ_CRASH("TestBufferList.cpp: overflow");
+    }
+    T* rv = static_cast<T*>(malloc(aNumElems * sizeof(T)));
+    if (!rv) {
+      MOZ_CRASH("TestBufferList.cpp: out of memory");
+    }
+    return rv;
+  }
+
+  void free_(void* aPtr) { free(aPtr); }
+
+  void reportAllocOverflow() const {}
+
+  bool checkSimulatedOOM() const { return true; }
+};
+
+typedef mozilla::BufferList<InfallibleAllocPolicy> BufferList;
+
+int main(void)
+{
+  const size_t kInitialSize = 16;
+  const size_t kInitialCapacity = 24;
+  const size_t kStandardCapacity = 32;
+
+  BufferList bl(kInitialSize, kInitialCapacity, kStandardCapacity);
+
+  memset(bl.Start(), 0x0c, kInitialSize);
+  MOZ_RELEASE_ASSERT(bl.Size() == kInitialSize);
+
+  // Simple iteration and access.
+
+  BufferList::IterImpl iter(bl.Iter());
+  MOZ_RELEASE_ASSERT(iter.RemainingInSegment() == kInitialSize);
+  MOZ_RELEASE_ASSERT(iter.HasRoomFor(kInitialSize));
+  MOZ_RELEASE_ASSERT(!iter.HasRoomFor(kInitialSize + 1));
+  MOZ_RELEASE_ASSERT(!iter.HasRoomFor(size_t(-1)));
+  MOZ_RELEASE_ASSERT(*iter.Data() == 0x0c);
+  MOZ_RELEASE_ASSERT(!iter.Done());
+
+  iter.Advance(bl, 4);
+  MOZ_RELEASE_ASSERT(iter.RemainingInSegment() == kInitialSize - 4);
+  MOZ_RELEASE_ASSERT(iter.HasRoomFor(kInitialSize - 4));
+  MOZ_RELEASE_ASSERT(*iter.Data() == 0x0c);
+  MOZ_RELEASE_ASSERT(!iter.Done());
+
+  iter.Advance(bl, 11);
+  MOZ_RELEASE_ASSERT(iter.RemainingInSegment() == kInitialSize - 4 - 11);
+  MOZ_RELEASE_ASSERT(iter.HasRoomFor(kInitialSize - 4 - 11));
+  MOZ_RELEASE_ASSERT(!iter.HasRoomFor(kInitialSize - 4 - 11 + 1));
+  MOZ_RELEASE_ASSERT(*iter.Data() == 0x0c);
+  MOZ_RELEASE_ASSERT(!iter.Done());
+
+  iter.Advance(bl, kInitialSize - 4 - 11);
+  MOZ_RELEASE_ASSERT(iter.RemainingInSegment() == 0);
+  MOZ_RELEASE_ASSERT(!iter.HasRoomFor(1));
+  MOZ_RELEASE_ASSERT(iter.Done());
+
+  // Writing to the buffer.
+
+  const size_t kSmallWrite = 16;
+
+  char toWrite[kSmallWrite];
+  memset(toWrite, 0x0a, kSmallWrite);
+  bl.WriteBytes(toWrite, kSmallWrite);
+
+  MOZ_RELEASE_ASSERT(bl.Size() == kInitialSize + kSmallWrite);
+
+  iter = bl.Iter();
+  iter.Advance(bl, kInitialSize);
+  MOZ_RELEASE_ASSERT(!iter.Done());
+  MOZ_RELEASE_ASSERT(iter.RemainingInSegment() == kInitialCapacity - kInitialSize);
+  MOZ_RELEASE_ASSERT(iter.HasRoomFor(kInitialCapacity - kInitialSize));
+  MOZ_RELEASE_ASSERT(*iter.Data() == 0x0a);
+
+  // AdvanceAcrossSegments.
+
+  iter = bl.Iter();
+  MOZ_RELEASE_ASSERT(iter.AdvanceAcrossSegments(bl, kInitialCapacity - 4));
+  MOZ_RELEASE_ASSERT(!iter.Done());
+  MOZ_RELEASE_ASSERT(iter.RemainingInSegment() == 4);
+  MOZ_RELEASE_ASSERT(iter.HasRoomFor(4));
+  MOZ_RELEASE_ASSERT(*iter.Data() == 0x0a);
+
+  iter = bl.Iter();
+  MOZ_RELEASE_ASSERT(iter.AdvanceAcrossSegments(bl, kInitialSize + kSmallWrite - 4));
+  MOZ_RELEASE_ASSERT(!iter.Done());
+  MOZ_RELEASE_ASSERT(iter.RemainingInSegment() == 4);
+  MOZ_RELEASE_ASSERT(iter.HasRoomFor(4));
+  MOZ_RELEASE_ASSERT(*iter.Data() == 0x0a);
+
+  MOZ_RELEASE_ASSERT(bl.Iter().AdvanceAcrossSegments(bl, kInitialSize + kSmallWrite - 1));
+  MOZ_RELEASE_ASSERT(bl.Iter().AdvanceAcrossSegments(bl, kInitialSize + kSmallWrite));
+  MOZ_RELEASE_ASSERT(!bl.Iter().AdvanceAcrossSegments(bl, kInitialSize + kSmallWrite + 1));
+  MOZ_RELEASE_ASSERT(!bl.Iter().AdvanceAcrossSegments(bl, size_t(-1)));
+
+  // Reading non-contiguous bytes.
+
+  char toRead[kSmallWrite];
+  iter = bl.Iter();
+  iter.Advance(bl, kInitialSize);
+  bl.ReadBytes(iter, toRead, kSmallWrite);
+  MOZ_RELEASE_ASSERT(memcmp(toRead, toWrite, kSmallWrite) == 0);
+  MOZ_RELEASE_ASSERT(iter.Done());
+
+  // Make sure reading up to the end of a segment advances the iter to the next
+  // segment.
+  iter = bl.Iter();
+  bl.ReadBytes(iter, toRead, kInitialSize);
+  MOZ_RELEASE_ASSERT(!iter.Done());
+  MOZ_RELEASE_ASSERT(iter.RemainingInSegment() == kInitialCapacity - kInitialSize);
+
+  const size_t kBigWrite = 1024;
+
+  char* toWriteBig = static_cast<char*>(malloc(kBigWrite));
+  for (unsigned i = 0; i < kBigWrite; i++) {
+    toWriteBig[i] = i % 37;
+  }
+  bl.WriteBytes(toWriteBig, kBigWrite);
+
+  char* toReadBig = static_cast<char*>(malloc(kBigWrite));
+  iter = bl.Iter();
+  MOZ_RELEASE_ASSERT(iter.AdvanceAcrossSegments(bl, kInitialSize + kSmallWrite));
+  bl.ReadBytes(iter, toReadBig, kBigWrite);
+  MOZ_RELEASE_ASSERT(memcmp(toReadBig, toWriteBig, kBigWrite) == 0);
+  MOZ_RELEASE_ASSERT(iter.Done());
+
+  free(toReadBig);
+  free(toWriteBig);
+
+  // Currently bl contains these segments:
+  // #0: offset 0, [0x0c]*16 + [0x0a]*8, size 24
+  // #1: offset 24, [0x0a]*8 + [i%37 for i in 0..24], size 32
+  // #2: offset 56, [i%37 for i in 24..56, size 32
+  // ...
+  // #32: offset 1016, [i%37 for i in 984..1016], size 32
+  // #33: offset 1048, [i%37 for i in 1016..1024], size 8
+
+  static size_t kTotalSize = kInitialSize + kSmallWrite + kBigWrite;
+
+  MOZ_RELEASE_ASSERT(bl.Size() == kTotalSize);
+
+  static size_t kLastSegmentSize = (kTotalSize - kInitialCapacity) % kStandardCapacity;
+
+  iter = bl.Iter();
+  MOZ_RELEASE_ASSERT(iter.AdvanceAcrossSegments(bl, kTotalSize - kLastSegmentSize - kStandardCapacity));
+  MOZ_RELEASE_ASSERT(iter.RemainingInSegment() == kStandardCapacity);
+  iter.Advance(bl, kStandardCapacity);
+  MOZ_RELEASE_ASSERT(iter.RemainingInSegment() == kLastSegmentSize);
+  MOZ_RELEASE_ASSERT(unsigned(*iter.Data()) == (kTotalSize - kLastSegmentSize - kInitialSize - kSmallWrite) % 37);
+
+  // Clear.
+
+  bl.Clear();
+  MOZ_RELEASE_ASSERT(bl.Size() == 0);
+  MOZ_RELEASE_ASSERT(bl.Iter().Done());
+
+  // Move assignment.
+
+  const size_t kSmallCapacity = 8;
+
+  BufferList bl2(0, kSmallCapacity, kSmallCapacity);
+  bl2.WriteBytes(toWrite, kSmallWrite);
+  bl2.WriteBytes(toWrite, kSmallWrite);
+  bl2.WriteBytes(toWrite, kSmallWrite);
+
+  bl = mozilla::Move(bl2);
+  MOZ_RELEASE_ASSERT(bl2.Size() == 0);
+  MOZ_RELEASE_ASSERT(bl2.Iter().Done());
+
+  iter = bl.Iter();
+  MOZ_RELEASE_ASSERT(iter.AdvanceAcrossSegments(bl, kSmallWrite * 3));
+  MOZ_RELEASE_ASSERT(iter.Done());
+
+  // MoveFallible
+
+  bool success;
+  bl2 = bl.MoveFallible<InfallibleAllocPolicy>(&success);
+  MOZ_RELEASE_ASSERT(success);
+  MOZ_RELEASE_ASSERT(bl.Size() == 0);
+  MOZ_RELEASE_ASSERT(bl.Iter().Done());
+  MOZ_RELEASE_ASSERT(bl2.Size() == kSmallWrite * 3);
+
+  iter = bl2.Iter();
+  MOZ_RELEASE_ASSERT(iter.AdvanceAcrossSegments(bl2, kSmallWrite * 3));
+  MOZ_RELEASE_ASSERT(iter.Done());
+
+  bl = bl2.MoveFallible<InfallibleAllocPolicy>(&success);
+
+  // Borrowing.
+
+  const size_t kBorrowStart = 4;
+  const size_t kBorrowSize = 24;
+
+  iter = bl.Iter();
+  iter.Advance(bl, kBorrowStart);
+  bl2 = bl.Borrow<InfallibleAllocPolicy>(iter, kBorrowSize, &success);
+  MOZ_RELEASE_ASSERT(success);
+  MOZ_RELEASE_ASSERT(bl2.Size() == kBorrowSize);
+
+  MOZ_RELEASE_ASSERT(iter.AdvanceAcrossSegments(bl, kSmallWrite * 3 - kBorrowSize - kBorrowStart));
+  MOZ_RELEASE_ASSERT(iter.Done());
+
+  iter = bl2.Iter();
+  MOZ_RELEASE_ASSERT(iter.AdvanceAcrossSegments(bl2, kBorrowSize));
+  MOZ_RELEASE_ASSERT(iter.Done());
+
+  BufferList::IterImpl iter1(bl.Iter()), iter2(bl2.Iter());
+  iter1.Advance(bl, kBorrowStart);
+  MOZ_RELEASE_ASSERT(iter1.Data() == iter2.Data());
+  MOZ_RELEASE_ASSERT(iter1.AdvanceAcrossSegments(bl, kBorrowSize - 5));
+  MOZ_RELEASE_ASSERT(iter2.AdvanceAcrossSegments(bl2, kBorrowSize - 5));
+  MOZ_RELEASE_ASSERT(iter1.Data() == iter2.Data());
+
+  // Extracting.
+
+  const size_t kExtractStart = 8;
+  const size_t kExtractSize = 24;
+  const size_t kExtractOverSize = 1000;
+
+  iter = bl.Iter();
+  iter.Advance(bl, kExtractStart);
+  bl2 = bl.Extract(iter, kExtractSize, &success);
+  MOZ_RELEASE_ASSERT(success);
+  MOZ_RELEASE_ASSERT(bl2.Size() == kExtractSize);
+
+  BufferList bl3 = bl.Extract(iter, kExtractOverSize, &success);
+  MOZ_RELEASE_ASSERT(!success);
+
+  MOZ_RELEASE_ASSERT(iter.AdvanceAcrossSegments(bl, kSmallWrite * 3 - kExtractSize - kExtractStart));
+  MOZ_RELEASE_ASSERT(iter.Done());
+
+  iter = bl2.Iter();
+  MOZ_RELEASE_ASSERT(iter.AdvanceAcrossSegments(bl2, kExtractSize));
+  MOZ_RELEASE_ASSERT(iter.Done());
+
+  return 0;
+}