/// a chunk at a time.
class raw_ostream {
private:
+ // Do not implement. raw_ostream is noncopyable.
+ void operator=(const raw_ostream &);
+ raw_ostream(const raw_ostream &);
+
/// The buffer is handled in such a way that the buffer is
/// uninitialized, unbuffered, or out of space when OutBufCur >=
/// OutBufEnd. Thus a single comparison suffices to determine if we
/// need to take the slow path to write a single character.
///
/// The buffer is in one of three states:
- /// 1. Unbuffered (Unbuffered == true)
- /// 1. Uninitialized (Unbuffered == false && OutBufStart == 0).
- /// 2. Buffered (Unbuffered == false && OutBufStart != 0 &&
+ /// 1. Unbuffered (BufferMode == Unbuffered)
+ /// 1. Uninitialized (BufferMode != Unbuffered && OutBufStart == 0).
+ /// 2. Buffered (BufferMode != Unbuffered && OutBufStart != 0 &&
/// OutBufEnd - OutBufStart >= 64).
+ ///
+ /// If buffered, then the raw_ostream owns the buffer if (BufferMode ==
+ /// InternalBuffer); otherwise the buffer has been set via SetBuffer and is
+ /// managed by the subclass.
+ ///
+ /// If a subclass installs an external buffer using SetBuffer then it can wait
+ /// for a \see write_impl() call to handle the data which has been put into
+ /// this buffer.
char *OutBufStart, *OutBufEnd, *OutBufCur;
- bool Unbuffered;
+
+ enum BufferKind {
+ Unbuffered = 0,
+ InternalBuffer,
+ ExternalBuffer
+ } BufferMode;
/// Error This flag is true if an error of any kind has been detected.
///
};
explicit raw_ostream(bool unbuffered=false)
- : Unbuffered(unbuffered), Error(false) {
+ : BufferMode(unbuffered ? Unbuffered : InternalBuffer), Error(false) {
// Start out ready to flush.
OutBufStart = OutBufEnd = OutBufCur = 0;
}
/// whether an output error has been encountered.
bool has_error() const {
return Error;
- };
+ }
/// clear_error - Set the flag read by has_error() to false. If the error
/// flag is set at the time when this raw_ostream's destructor is called,
/// after handling the error to avoid this behavior.
void clear_error() {
Error = false;
- };
+ }
//===--------------------------------------------------------------------===//
// Configuration Interface
//===--------------------------------------------------------------------===//
- /// SetBufferSize - Set the internal buffer size to the specified amount
- /// instead of the default.
- void SetBufferSize(size_t Size=4096) {
- assert(Size >= 64 &&
- "Buffer size must be somewhat large for invariants to hold");
+ /// SetBuffered - Set the stream to be buffered, with an automatically
+ /// determined buffer size.
+ void SetBuffered();
+
+ /// SetBufferSize - Set the stream to be buffered, using the
+ /// specified buffer size.
+ void SetBufferSize(size_t Size) {
flush();
+ SetBufferAndMode(new char[Size], Size, InternalBuffer);
+ }
- delete [] OutBufStart;
- OutBufStart = new char[Size];
- OutBufEnd = OutBufStart+Size;
- OutBufCur = OutBufStart;
- Unbuffered = false;
+ size_t GetBufferSize() {
+ // If we're supposed to be buffered but haven't actually gotten around
+ // to allocating the buffer yet, return the value that would be used.
+ if (!Unbuffered && !OutBufStart)
+ return preferred_buffer_size();
+
+ // Otherwise just return the size of the allocated buffer.
+ return OutBufEnd - OutBufStart;
}
- /// SetUnbuffered - Set the streams buffering status. When
- /// unbuffered the stream will flush after every write. This routine
+ /// SetUnbuffered - Set the stream to be unbuffered. When
+ /// unbuffered, the stream will flush after every write. This routine
/// will also flush the buffer immediately when the stream is being
/// set to unbuffered.
void SetUnbuffered() {
flush();
-
- delete [] OutBufStart;
- OutBufStart = OutBufEnd = OutBufCur = 0;
- Unbuffered = true;
+ SetBufferAndMode(0, 0, Unbuffered);
}
size_t GetNumBytesInBuffer() const {
return *this;
}
- raw_ostream &operator<<(const std::string& Str) {
+ raw_ostream &operator<<(const std::string &Str) {
+ // Avoid the fast path, it would only increase code size for a marginal win.
+
write(Str.data(), Str.length());
return *this;
}
return *this;
}
+ /// write_hex - Output \arg N in hexadecimal, without any prefix or padding.
+ raw_ostream &write_hex(unsigned long long N);
+
raw_ostream &write(unsigned char C);
raw_ostream &write(const char *Ptr, size_t Size);
/// by subclasses. This writes the \args Size bytes starting at
/// \arg Ptr to the underlying stream.
///
+ /// This function is guaranteed to only be called at a point at which it is
+ /// safe for the subclass to install a new buffer via SetBuffer.
+ ///
+ /// \arg Ptr - The start of the data to be written. For buffered streams this
+ /// is guaranteed to be the start of the buffer.
+ /// \arg Size - The number of bytes to be written.
+ ///
/// \invariant { Size > 0 }
virtual void write_impl(const char *Ptr, size_t Size) = 0;
virtual uint64_t current_pos() = 0;
protected:
+ /// SetBuffer - Use the provided buffer as the raw_ostream buffer. This is
+ /// intended for use only by subclasses which can arrange for the output to go
+ /// directly into the desired output buffer, instead of being copied on each
+ /// flush.
+ void SetBuffer(char *BufferStart, size_t Size) {
+ SetBufferAndMode(BufferStart, Size, ExternalBuffer);
+ }
+
+ /// preferred_buffer_size - Return an efficient buffer size for the
+ /// underlying output mechanism.
+ virtual size_t preferred_buffer_size();
+
/// error_detected - Set the flag indicating that an output error has
/// been encountered.
void error_detected() { Error = true; }
+ /// getBufferStart - Return the beginning of the current stream buffer, or 0
+ /// if the stream is unbuffered.
+ const char *getBufferStart() const { return OutBufStart; }
+
//===--------------------------------------------------------------------===//
// Private Interface
//===--------------------------------------------------------------------===//
private:
+ /// SetBufferAndMode - Install the given buffer and mode.
+ void SetBufferAndMode(char *BufferStart, size_t Size, BufferKind Mode);
+
/// flush_nonempty - Flush the current buffer, which is known to be
/// non-empty. This outputs the currently buffered data and resets
/// the buffer to empty.
void flush_nonempty();
+
+ /// copy_to_buffer - Copy data into the buffer. Size must not be
+ /// greater than the number of unused bytes in the buffer.
+ void copy_to_buffer(const char *Ptr, size_t Size);
};
//===----------------------------------------------------------------------===//
/// counting the bytes currently in the buffer.
virtual uint64_t current_pos() { return pos; }
+ /// preferred_buffer_size - Determine an efficient buffer size.
+ virtual size_t preferred_buffer_size();
+
public:
/// raw_fd_ostream - Open the specified file for writing. If an
/// error occurs, information about the error is put into ErrorInfo,
/// close - Manually flush the stream and close the file.
void close();
- /// tell - Return the current offset with the file.
- uint64_t tell() { return pos + GetNumBytesInBuffer(); }
-
/// seek - Flushes the stream and repositions the underlying file descriptor
/// positition to the offset specified from the beginning of the file.
uint64_t seek(uint64_t off);
public:
raw_os_ostream(std::ostream &O) : OS(O) {}
~raw_os_ostream();
-
- /// tell - Return the current offset with the stream.
- uint64_t tell();
};
/// raw_string_ostream - A raw_ostream that writes to an std::string. This is a
explicit raw_string_ostream(std::string &O) : OS(O) {}
~raw_string_ostream();
- /// tell - Return the current offset with the stream.
- uint64_t tell() { return OS.size() + GetNumBytesInBuffer(); }
-
/// str - Flushes the stream contents to the target string and returns
/// the string's reference.
std::string& str() {
/// counting the bytes currently in the buffer.
virtual uint64_t current_pos();
public:
- explicit raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {}
+ /// Construct a new raw_svector_ostream.
+ ///
+ /// \arg O - The vector to write to; this *must* have at least 128 bytes of
+ /// free space in it.
+ explicit raw_svector_ostream(SmallVectorImpl<char> &O);
~raw_svector_ostream();
-
- /// tell - Return the current offset with the stream.
- uint64_t tell();
};
/// raw_null_ostream - A raw_ostream that discards all output.
public:
explicit raw_null_ostream() {}
+ ~raw_null_ostream();
};
} // end llvm namespace
projects / oota-llvm.git / blobdiff