commit 96c6985b5327845be772c2bc13567c2967969cc7
author Zachary Turner <zturner@google.com> Mon Nov 27 18:48:37 2017 +0000
committer Zachary Turner <zturner@google.com> Mon Nov 27 18:48:37 2017 +0000
tree 630b1fba2331a97d751864515dfa76eb6f168d15
parent ec6e21427275ce1cdb2580aaa4167b143aab049c

[BinaryStream] Support growable streams.

The existing library assumed that a stream's length would never
change.  This makes some things simpler, but it's not flexible
enough for what we need, especially for writable streams where
what you really want is for each call to write to actually append.

llvm-svn: 319070

llvm/lib/Support/BinaryStreamRef.cpp

diff --git a/llvm/lib/Support/BinaryStreamRef.cpp b/llvm/lib/Support/BinaryStreamRef.cpp
index 70ee156..60a03fe 100644
--- a/llvm/lib/Support/BinaryStreamRef.cpp
+++ b/llvm/lib/Support/BinaryStreamRef.cpp
@@ -66,9 +66,9 @@
 }
 
 BinaryStreamRef::BinaryStreamRef(BinaryStream &Stream)
-    : BinaryStreamRef(Stream, 0, Stream.getLength()) {}
+    : BinaryStreamRefBase(Stream) {}
 BinaryStreamRef::BinaryStreamRef(BinaryStream &Stream, uint32_t Offset,
-                                 uint32_t Length)
+                                 Optional<uint32_t> Length)
     : BinaryStreamRefBase(Stream, Offset, Length) {}
 BinaryStreamRef::BinaryStreamRef(ArrayRef<uint8_t> Data, endianness Endian)
     : BinaryStreamRefBase(std::make_shared<ArrayRefImpl>(Data, Endian), 0,
@@ -79,14 +79,14 @@
 
 Error BinaryStreamRef::readBytes(uint32_t Offset, uint32_t Size,
                                  ArrayRef<uint8_t> &Buffer) const {
-  if (auto EC = checkOffset(Offset, Size))
+  if (auto EC = checkOffsetForRead(Offset, Size))
     return EC;
   return BorrowedImpl->readBytes(ViewOffset + Offset, Size, Buffer);
 }
 
 Error BinaryStreamRef::readLongestContiguousChunk(
     uint32_t Offset, ArrayRef<uint8_t> &Buffer) const {
-  if (auto EC = checkOffset(Offset, 1))
+  if (auto EC = checkOffsetForRead(Offset, 1))
     return EC;
 
   if (auto EC =
@@ -95,18 +95,18 @@
   // This StreamRef might refer to a smaller window over a larger stream.  In
   // that case we will have read out more bytes than we should return, because
   // we should not read past the end of the current view.
-  uint32_t MaxLength = Length - Offset;
+  uint32_t MaxLength = getLength() - Offset;
   if (Buffer.size() > MaxLength)
     Buffer = Buffer.slice(0, MaxLength);
   return Error::success();
 }
 
 WritableBinaryStreamRef::WritableBinaryStreamRef(WritableBinaryStream &Stream)
-    : WritableBinaryStreamRef(Stream, 0, Stream.getLength()) {}
+    : BinaryStreamRefBase(Stream) {}
 
 WritableBinaryStreamRef::WritableBinaryStreamRef(WritableBinaryStream &Stream,
                                                  uint32_t Offset,
-                                                 uint32_t Length)
+                                                 Optional<uint32_t> Length)
     : BinaryStreamRefBase(Stream, Offset, Length) {}
 
 WritableBinaryStreamRef::WritableBinaryStreamRef(MutableArrayRef<uint8_t> Data,
@@ -117,7 +117,7 @@
 
 Error WritableBinaryStreamRef::writeBytes(uint32_t Offset,
                                           ArrayRef<uint8_t> Data) const {
-  if (auto EC = checkOffset(Offset, Data.size()))
+  if (auto EC = checkOffsetForWrite(Offset, Data.size()))
     return EC;
 
   return BorrowedImpl->writeBytes(ViewOffset + Offset, Data);