llvm-mirror/lib/Support/DataStream.cpp
Chandler Carruth a490793037 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

llvm-svn: 169131
2012-12-03 16:50:05 +00:00

99 lines
2.9 KiB
C++

//===--- llvm/Support/DataStream.cpp - Lazy streamed data -----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements DataStreamer, which fetches bytes of Data from
// a stream source. It provides support for streaming (lazy reading) of
// bitcode. An example implementation of streaming from a file or stdin
// is included.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "Data-stream"
#include "llvm/Support/DataStream.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/Program.h"
#include "llvm/Support/system_error.h"
#include <cerrno>
#include <cstdio>
#include <string>
#if !defined(_MSC_VER) && !defined(__MINGW32__)
#include <unistd.h>
#else
#include <io.h>
#endif
#include <fcntl.h>
using namespace llvm;
// Interface goals:
// * StreamableMemoryObject doesn't care about complexities like using
// threads/async callbacks to actually overlap download+compile
// * Don't want to duplicate Data in memory
// * Don't need to know total Data len in advance
// Non-goals:
// StreamableMemoryObject already has random access so this interface only does
// in-order streaming (no arbitrary seeking, else we'd have to buffer all the
// Data here in addition to MemoryObject). This also means that if we want
// to be able to to free Data, BitstreamBytes/BitcodeReader will implement it
STATISTIC(NumStreamFetches, "Number of calls to Data stream fetch");
namespace llvm {
DataStreamer::~DataStreamer() {}
}
namespace {
// Very simple stream backed by a file. Mostly useful for stdin and debugging;
// actual file access is probably still best done with mmap.
class DataFileStreamer : public DataStreamer {
int Fd;
public:
DataFileStreamer() : Fd(0) {}
virtual ~DataFileStreamer() {
close(Fd);
}
virtual size_t GetBytes(unsigned char *buf, size_t len) LLVM_OVERRIDE {
NumStreamFetches++;
return read(Fd, buf, len);
}
error_code OpenFile(const std::string &Filename) {
if (Filename == "-") {
Fd = 0;
sys::Program::ChangeStdinToBinary();
return error_code::success();
}
int OpenFlags = O_RDONLY;
#ifdef O_BINARY
OpenFlags |= O_BINARY; // Open input file in binary mode on win32.
#endif
Fd = ::open(Filename.c_str(), OpenFlags);
if (Fd == -1)
return error_code(errno, posix_category());
return error_code::success();
}
};
}
namespace llvm {
DataStreamer *getDataFileStreamer(const std::string &Filename,
std::string *StrError) {
DataFileStreamer *s = new DataFileStreamer();
if (error_code e = s->OpenFile(Filename)) {
*StrError = std::string("Could not open ") + Filename + ": " +
e.message() + "\n";
return NULL;
}
return s;
}
}