#include "llvm/ADT/StringExtras.h"
#include <cassert>
#include <string>
-
-#ifdef HAVE_BZIP2
-#include <bzlib.h>
-#endif
-
-#ifdef HAVE_ZLIB
-#include <zlib.h>
-#endif
+#include "bzip2/bzlib.h"
namespace {
+enum CompressionTypes {
+ COMP_TYPE_NONE = '0',
+ COMP_TYPE_BZIP2 = '2',
+};
+
inline int getdata(char*& buffer, unsigned& size,
llvm::Compressor::OutputDataCallback* cb, void* context) {
buffer = 0;
void NULLCOMP_end(NULLCOMP_stream* strm) {
}
+/// This structure is only used when a bytecode file is compressed.
+/// As bytecode is being decompressed, the memory buffer might need
+/// to be reallocated. The buffer allocation is handled in a callback
+/// and this structure is needed to retain information across calls
+/// to the callback.
+/// @brief An internal buffer object used for handling decompression
+struct BufferContext {
+ char* buff;
+ unsigned size;
+ BufferContext(unsigned compressedSize ) {
+ // Null to indicate malloc of a new block
+ buff = 0;
+
+ // Compute the initial length of the uncompression buffer. Note that this
+ // is twice the length of the compressed buffer and will be doubled again
+ // in the callback for an initial allocation of 4x compressedSize. This
+ // calculation is based on the typical compression ratio of bzip2 on LLVM
+ // bytecode files which typically ranges in the 50%-75% range. Since we
+ // tyipcally get at least 50%, doubling is insufficient. By using a 4x
+ // multiplier on the first allocation, we minimize the impact of having to
+ // copy the buffer on reallocation.
+ size = compressedSize*2;
+ }
+
+ /// This function handles allocation of the buffer used for decompression of
+ /// compressed bytecode files. It is called by Compressor::decompress which is
+ /// called by BytecodeReader::ParseBytecode.
+ static unsigned callback(char*&buff, unsigned& sz, void* ctxt){
+ // Case the context variable to our BufferContext
+ BufferContext* bc = reinterpret_cast<BufferContext*>(ctxt);
+
+ // Compute the new, doubled, size of the block
+ unsigned new_size = bc->size * 2;
+
+ // Extend or allocate the block (realloc(0,n) == malloc(n))
+ char* new_buff = (char*) ::realloc(bc->buff, new_size);
+
+ // Figure out what to return to the Compressor. If this is the first call,
+ // then bc->buff will be null. In this case we want to return the entire
+ // buffer because there was no previous allocation. Otherwise, when the
+ // buffer is reallocated, we save the new base pointer in the
+ // BufferContext.buff field but return the address of only the extension,
+ // mid-way through the buffer (since its size was doubled). Furthermore,
+ // the sz result must be 1/2 the total size of the buffer.
+ if (bc->buff == 0 ) {
+ buff = bc->buff = new_buff;
+ sz = new_size;
+ } else {
+ bc->buff = new_buff;
+ buff = new_buff + bc->size;
+ sz = bc->size;
+ }
+
+ // Retain the size of the allocated block
+ bc->size = new_size;
+
+ // Make sure we fail (return 1) if we didn't get any memory.
+ return (bc->buff == 0 ? 1 : 0);
+ }
+};
+
+// This structure retains the context when compressing the bytecode file. The
+// WriteCompressedData function below uses it to keep track of the previously
+// filled chunk of memory (which it writes) and how many bytes have been
+// written.
+struct WriterContext {
+ // Initialize the context
+ WriterContext(std::ostream*OS, unsigned CS)
+ : chunk(0), sz(0), written(0), compSize(CS), Out(OS) {}
+
+ // Make sure we clean up memory
+ ~WriterContext() {
+ if (chunk)
+ delete [] chunk;
+ }
+
+ // Write the chunk
+ void write(unsigned size = 0) {
+ unsigned write_size = (size == 0 ? sz : size);
+ Out->write(chunk,write_size);
+ written += write_size;
+ delete [] chunk;
+ chunk = 0;
+ sz = 0;
+ }
+
+ // This function is a callback used by the Compressor::compress function to
+ // allocate memory for the compression buffer. This function fulfills that
+ // responsibility but also writes the previous (now filled) buffer out to the
+ // stream.
+ static unsigned callback(char*& buffer, unsigned& size, void* context) {
+ // Cast the context to the structure it must point to.
+ WriterContext* ctxt =
+ reinterpret_cast<WriterContext*>(context);
+
+ // If there's a previously allocated chunk, it must now be filled with
+ // compressed data, so we write it out and deallocate it.
+ if (ctxt->chunk != 0 && ctxt->sz > 0 ) {
+ ctxt->write();
+ }
+
+ // Compute the size of the next chunk to allocate. We attempt to allocate
+ // enough memory to handle the compression in a single memory allocation. In
+ // general, the worst we do on compression of bytecode is about 50% so we
+ // conservatively estimate compSize / 2 as the size needed for the
+ // compression buffer. compSize is the size of the compressed data, provided
+ // by WriteBytecodeToFile.
+ size = ctxt->sz = ctxt->compSize / 2;
+
+ // Allocate the chunks
+ buffer = ctxt->chunk = new char [size];
+
+ // We must return 1 if the allocation failed so that the Compressor knows
+ // not to use the buffer pointer.
+ return (ctxt->chunk == 0 ? 1 : 0);
+ }
+
+ char* chunk; // pointer to the chunk of memory filled by compression
+ unsigned sz; // size of chunk
+ unsigned written; // aggregate total of bytes written in all chunks
+ unsigned compSize; // size of the uncompressed buffer
+ std::ostream* Out; // The stream we write the data to.
+};
+
}
namespace llvm {
// Compress in one of three ways
-uint64_t Compressor::compress(char* in, unsigned size, OutputDataCallback* cb,
- Algorithm hint, void* context ) {
+uint64_t Compressor::compress(const char* in, unsigned size,
+ OutputDataCallback* cb, void* context ) {
assert(in && "Can't compress null buffer");
assert(size && "Can't compress empty buffer");
assert(cb && "Can't compress without a callback function");
uint64_t result = 0;
- switch (hint) {
- case COMP_TYPE_BZIP2: {
-#if defined(HAVE_BZIP2)
- // Set up the bz_stream
- bz_stream bzdata;
- bzdata.bzalloc = 0;
- bzdata.bzfree = 0;
- bzdata.opaque = 0;
- bzdata.next_in = in;
- bzdata.avail_in = size;
- bzdata.next_out = 0;
- bzdata.avail_out = 0;
- switch ( BZ2_bzCompressInit(&bzdata, 5, 0, 100) ) {
- case BZ_CONFIG_ERROR: throw std::string("bzip2 library mis-compiled");
- case BZ_PARAM_ERROR: throw std::string("Compressor internal error");
- case BZ_MEM_ERROR: throw std::string("Out of memory");
- case BZ_OK:
- default:
- break;
- }
-
- // Get a block of memory
- if (0 != getdata(bzdata.next_out, bzdata.avail_out,cb,context)) {
- BZ2_bzCompressEnd(&bzdata);
- throw std::string("Can't allocate output buffer");
- }
-
- // Put compression code in first byte
- (*bzdata.next_out++) = COMP_TYPE_BZIP2;
- bzdata.avail_out--;
-
- // Compress it
- int bzerr = BZ_FINISH_OK;
- while (BZ_FINISH_OK == (bzerr = BZ2_bzCompress(&bzdata, BZ_FINISH))) {
- if (0 != getdata(bzdata.next_out, bzdata.avail_out,cb,context)) {
- BZ2_bzCompressEnd(&bzdata);
- throw std::string("Can't allocate output buffer");
- }
- }
- switch (bzerr) {
- case BZ_SEQUENCE_ERROR:
- case BZ_PARAM_ERROR: throw std::string("Param/Sequence error");
- case BZ_FINISH_OK:
- case BZ_STREAM_END: break;
- default: throw std::string("Oops: ") + utostr(unsigned(bzerr));
- }
-
- // Finish
- result = (static_cast<uint64_t>(bzdata.total_out_hi32) << 32) |
- bzdata.total_out_lo32 + 1;
+ // For small files, we just don't bother compressing. bzip2 isn't very good
+ // with tiny files and can actually make the file larger, so we just avoid
+ // it altogether.
+ if (size > 64*1024) {
+ // Set up the bz_stream
+ bz_stream bzdata;
+ bzdata.bzalloc = 0;
+ bzdata.bzfree = 0;
+ bzdata.opaque = 0;
+ bzdata.next_in = (char*)in;
+ bzdata.avail_in = size;
+ bzdata.next_out = 0;
+ bzdata.avail_out = 0;
+ switch ( BZ2_bzCompressInit(&bzdata, 5, 0, 100) ) {
+ case BZ_CONFIG_ERROR: throw std::string("bzip2 library mis-compiled");
+ case BZ_PARAM_ERROR: throw std::string("Compressor internal error");
+ case BZ_MEM_ERROR: throw std::string("Out of memory");
+ case BZ_OK:
+ default:
+ break;
+ }
+ // Get a block of memory
+ if (0 != getdata(bzdata.next_out, bzdata.avail_out,cb,context)) {
BZ2_bzCompressEnd(&bzdata);
- break;
-#else
- // FALL THROUGH
-#endif
+ throw std::string("Can't allocate output buffer");
}
- case COMP_TYPE_ZLIB: {
-#if defined(HAVE_ZLIB)
- z_stream zdata;
- zdata.zalloc = Z_NULL;
- zdata.zfree = Z_NULL;
- zdata.opaque = Z_NULL;
- zdata.next_in = reinterpret_cast<Bytef*>(in);
- zdata.avail_in = size;
- if (Z_OK != deflateInit(&zdata,6))
- throw std::string(zdata.msg ? zdata.msg : "zlib error");
-
- if (0 != getdata((char*&)(zdata.next_out), zdata.avail_out,cb,context)) {
- deflateEnd(&zdata);
- throw std::string("Can't allocate output buffer");
- }
-
- (*zdata.next_out++) = COMP_TYPE_ZLIB;
- zdata.avail_out--;
-
- int flush = 0;
- while ( Z_OK == deflate(&zdata,0) && zdata.avail_out == 0) {
- if (0 != getdata((char*&)zdata.next_out, zdata.avail_out, cb,context)) {
- deflateEnd(&zdata);
- throw std::string("Can't allocate output buffer");
- }
- }
+ // Put compression code in first byte
+ (*bzdata.next_out++) = COMP_TYPE_BZIP2;
+ bzdata.avail_out--;
- while ( Z_STREAM_END != deflate(&zdata, Z_FINISH)) {
- if (0 != getdata((char*&)zdata.next_out, zdata.avail_out, cb,context)) {
- deflateEnd(&zdata);
- throw std::string("Can't allocate output buffer");
- }
+ // Compress it
+ int bzerr = BZ_FINISH_OK;
+ while (BZ_FINISH_OK == (bzerr = BZ2_bzCompress(&bzdata, BZ_FINISH))) {
+ if (0 != getdata(bzdata.next_out, bzdata.avail_out,cb,context)) {
+ BZ2_bzCompressEnd(&bzdata);
+ throw std::string("Can't allocate output buffer");
}
+ }
+ switch (bzerr) {
+ case BZ_SEQUENCE_ERROR:
+ case BZ_PARAM_ERROR: throw std::string("Param/Sequence error");
+ case BZ_FINISH_OK:
+ case BZ_STREAM_END: break;
+ default: throw std::string("Oops: ") + utostr(unsigned(bzerr));
+ }
- result = static_cast<uint64_t>(zdata.total_out) + 1;
- deflateEnd(&zdata);
- break;
+ // Finish
+ result = (static_cast<uint64_t>(bzdata.total_out_hi32) << 32) |
+ bzdata.total_out_lo32 + 1;
-#else
- // FALL THROUGH
-#endif
+ BZ2_bzCompressEnd(&bzdata);
+ } else {
+ // Do null compression, for small files
+ NULLCOMP_stream sdata;
+ sdata.next_in = (char*)in;
+ sdata.avail_in = size;
+ NULLCOMP_init(&sdata);
+
+ if (0 != getdata(sdata.next_out, sdata.avail_out,cb,context)) {
+ throw std::string("Can't allocate output buffer");
}
- case COMP_TYPE_SIMPLE: {
- NULLCOMP_stream sdata;
- sdata.next_in = in;
- sdata.avail_in = size;
- NULLCOMP_init(&sdata);
+ *(sdata.next_out++) = COMP_TYPE_NONE;
+ sdata.avail_out--;
+ while (!NULLCOMP_compress(&sdata)) {
if (0 != getdata(sdata.next_out, sdata.avail_out,cb,context)) {
throw std::string("Can't allocate output buffer");
}
+ }
- *(sdata.next_out++) = COMP_TYPE_SIMPLE;
- sdata.avail_out--;
+ result = sdata.output_count + 1;
+ NULLCOMP_end(&sdata);
+ }
+ return result;
+}
- while (!NULLCOMP_compress(&sdata)) {
- if (0 != getdata(sdata.next_out, sdata.avail_out,cb,context)) {
- throw std::string("Can't allocate output buffer");
- }
- }
+uint64_t
+Compressor::compressToNewBuffer(const char* in, unsigned size, char*&out) {
+ BufferContext bc(size);
+ unsigned result = compress(in,size,BufferContext::callback,(void*)&bc);
+ out = bc.buff;
+ return result;
+}
- result = sdata.output_count + 1;
- NULLCOMP_end(&sdata);
- break;
- }
- default:
- throw std::string("Invalid compression type hint");
+uint64_t
+Compressor::compressToStream(const char*in, unsigned size, std::ostream& out) {
+ // Set up the context and writer
+ WriterContext ctxt(&out,size / 2);
+
+ // Compress everything after the magic number (which we'll alter)
+ uint64_t zipSize = Compressor::compress(in,size,
+ WriterContext::callback, (void*)&ctxt);
+
+ if (ctxt.chunk) {
+ ctxt.write(zipSize - ctxt.written);
}
- return result;
+ return zipSize;
}
// Decompress in one of three ways
-uint64_t Compressor::decompress(char *in, unsigned size,
+uint64_t Compressor::decompress(const char *in, unsigned size,
OutputDataCallback* cb, void* context) {
assert(in && "Can't decompress null buffer");
assert(size > 1 && "Can't decompress empty buffer");
switch (*in++) {
case COMP_TYPE_BZIP2: {
-#if !defined(HAVE_BZIP2)
- throw std::string("Can't decompress BZIP2 data");
-#else
// Set up the bz_stream
bz_stream bzdata;
bzdata.bzalloc = 0;
bzdata.bzfree = 0;
bzdata.opaque = 0;
- bzdata.next_in = in;
+ bzdata.next_in = (char*)in;
bzdata.avail_in = size - 1;
bzdata.next_out = 0;
bzdata.avail_out = 0;
bzdata.total_out_lo32;
BZ2_bzDecompressEnd(&bzdata);
break;
-#endif
}
- case COMP_TYPE_ZLIB: {
-#if !defined(HAVE_ZLIB)
- throw std::string("Can't decompress ZLIB data");
-#else
- z_stream zdata;
- zdata.zalloc = Z_NULL;
- zdata.zfree = Z_NULL;
- zdata.opaque = Z_NULL;
- zdata.next_in = reinterpret_cast<Bytef*>(in);
- zdata.avail_in = size - 1;
- if ( Z_OK != inflateInit(&zdata))
- throw std::string(zdata.msg ? zdata.msg : "zlib error");
-
- if (0 != getdata((char*&)zdata.next_out, zdata.avail_out,cb,context)) {
- inflateEnd(&zdata);
- throw std::string("Can't allocate output buffer");
- }
-
- int zerr = Z_OK;
- while (Z_OK == (zerr = inflate(&zdata,0))) {
- if (0 != getdata((char*&)zdata.next_out, zdata.avail_out,cb,context)) {
- inflateEnd(&zdata);
- throw std::string("Can't allocate output buffer");
- }
- }
-
- if (zerr != Z_STREAM_END)
- throw std::string(zdata.msg?zdata.msg:"zlib error");
-
- result = static_cast<uint64_t>(zdata.total_out);
- inflateEnd(&zdata);
- break;
-#endif
- }
-
- case COMP_TYPE_SIMPLE: {
+ case COMP_TYPE_NONE: {
NULLCOMP_stream sdata;
- sdata.next_in = in;
+ sdata.next_in = (char*)in;
sdata.avail_in = size - 1;
NULLCOMP_init(&sdata);
return result;
}
+uint64_t
+Compressor::decompressToNewBuffer(const char* in, unsigned size, char*&out) {
+ BufferContext bc(size);
+ unsigned result = decompress(in,size,BufferContext::callback,(void*)&bc);
+ out = bc.buff;
+ return result;
+}
+
+uint64_t
+Compressor::decompressToStream(const char*in, unsigned size, std::ostream& out){
+ // Set up the context and writer
+ WriterContext ctxt(&out,size / 2);
+
+ // Compress everything after the magic number (which we'll alter)
+ uint64_t zipSize = Compressor::decompress(in,size,
+ WriterContext::callback, (void*)&ctxt);
+
+ if (ctxt.chunk) {
+ ctxt.write(zipSize - ctxt.written);
+ }
+ return zipSize;
+}
+
}
// vim: sw=2 ai
projects / oota-llvm.git / blobdiff