Add a context for the callback so different compression scenarios can be

distinguished. Tidy up documentation.  Thanks, Chris.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16652 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 29 insertions, 27 deletions

diff --git a/include/llvm/Support/Compressor.h b/include/llvm/Support/Compressor.h
index eea98ebe13..15761a07d6 100644
--- a/include/llvm/Support/Compressor.h
+++ b/include/llvm/Support/Compressor.h
@@ -14,25 +14,25 @@
 #ifndef LLVM_SUPPORT_COMPRESSOR_H
 #define LLVM_SUPPORT_COMPRESSOR_H
 
-#include <llvm/Support/DataTypes.h>
+#include "llvm/Support/DataTypes.h"
 
 namespace llvm {
 
   /// This class provides an abstraction for compressing a block of memory using
   /// a standard compression utility such as bzip2 or libz. This interface
-  /// allos us to abstraction the notion of compression and deal with alternate
+  /// allows us to abstract the notion of compression and deal with alternate
   /// compression scheme availability depending on the configured platform. This
   /// facility will always favor a bzip2 implementation if its available.
-  /// Otherwise, libz will be used if its available. If neither zlib nor bzip2
+  /// Otherwise, libz will be used if it is available. If neither zlib nor bzip2
   /// are available, a very simple algorithm provided by the Compressor class
-  /// will be used The type of compression used can be determined by inspecting 
+  /// will be used. The type of compression used can be determined by inspecting 
   /// the first byte of the compressed output. ASCII values '0', '1', and '2', 
   /// denote the compression type as given in the Algorithm enumeration below.
   /// The Compressor is intended for use with memory mapped files where the 
   /// entire data block to be compressed or decompressed is available in 
-  /// memory. Output, however, can be gathered in repeated calls to a callback.
+  /// memory. However, output can be gathered in repeated calls to a callback.
   /// @since 1.4
-  /// @brief An abstraction for memory to memory data compression
+  /// @brief An abstraction for memory to memory data (de)compression
   class Compressor {
     /// @name Types
     /// @{
@@ -50,7 +50,8 @@ namespace llvm {
       /// @returns 0 for success, 1 for failure
       /// @throws nothing
       /// @brief Output callback function type
-      typedef unsigned (OutputDataCallback)(char*& buffer, unsigned& size);
+      typedef unsigned (OutputDataCallback)(char*& buffer, unsigned& size,
+                                            void* context);
 
     /// @}
     /// @name Methods
@@ -72,7 +73,8 @@ namespace llvm {
       /// @returns the total size of the compressed data
       /// @brief Compress a block of memory.
       static uint64_t compress(char* in, unsigned size, OutputDataCallback* cb,
-                               Algorithm hint = COMP_TYPE_BZIP2);
+                               Algorithm hint = COMP_TYPE_BZIP2,
+                               void* context = 0);
 
       /// This function does the decompression work. The block of memory
       /// starting at \p in and extending for \p size bytes is decompressed. The
@@ -88,7 +90,7 @@ namespace llvm {
       /// @returns the total size of the decompressed data
       /// @brief Decompress a block of memory.
       static uint64_t decompress(char *in, unsigned size, 
-                                 OutputDataCallback* cb);
+                                 OutputDataCallback* cb, void* context = 0);
 
     /// @}
   };
diff --git a/lib/Support/Compressor.cpp b/lib/Support/Compressor.cpp
index d939885945..e9bb781a2c 100644
--- a/lib/Support/Compressor.cpp
+++ b/lib/Support/Compressor.cpp
@@ -35,10 +35,10 @@
 namespace {
 
 inline int getdata(char*& buffer, unsigned& size, 
-                   llvm::Compressor::OutputDataCallback* cb) {
+                   llvm::Compressor::OutputDataCallback* cb, void* context) {
   buffer = 0;
   size = 0;
-  int result = (*cb)(buffer, size);
+  int result = (*cb)(buffer, size, context);
   assert(buffer != 0 && "Invalid result from Compressor callback");
   assert(size != 0 && "Invalid result from Compressor callback");
   return result;
@@ -255,8 +255,8 @@ void RLCOMP_end(RLCOMP_stream* strm) {
 namespace llvm {
 
 // Compress in one of three ways
-uint64_t Compressor::compress(char* in, unsigned size, 
-                              OutputDataCallback* cb, Algorithm hint) {
+uint64_t Compressor::compress(char* in, unsigned size, OutputDataCallback* cb, 
+                              Algorithm hint, 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");
@@ -285,7 +285,7 @@ uint64_t Compressor::compress(char* in, unsigned size,
       }
 
       // Get a block of memory
-      if (0 != getdata(bzdata.next_out, bzdata.avail_out,cb)) {
+      if (0 != getdata(bzdata.next_out, bzdata.avail_out,cb,context)) {
         BZ2_bzCompressEnd(&bzdata);
         throw std::string("Can't allocate output buffer");
       }
@@ -297,7 +297,7 @@ uint64_t Compressor::compress(char* in, unsigned size,
       // 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)) {
+        if (0 != getdata(bzdata.next_out, bzdata.avail_out,cb,context)) {
           BZ2_bzCompressEnd(&bzdata);
           throw std::string("Can't allocate output buffer");
         }
@@ -332,7 +332,7 @@ uint64_t Compressor::compress(char* in, unsigned size,
       if (Z_OK != deflateInit(&zdata,Z_BEST_COMPRESSION))
         throw std::string(zdata.msg ? zdata.msg : "zlib error");
 
-      if (0 != getdata((char*&)(zdata.next_out), zdata.avail_out,cb)) {
+      if (0 != getdata((char*&)(zdata.next_out), zdata.avail_out,cb,context)) {
         deflateEnd(&zdata);
         throw std::string("Can't allocate output buffer");
       }
@@ -342,14 +342,14 @@ uint64_t Compressor::compress(char* in, unsigned size,
 
       int flush = 0;
       while ( Z_OK == deflate(&zdata,0) && zdata.avail_out == 0) {
-        if (0 != getdata((char*&)zdata.next_out, zdata.avail_out, cb)) {
+        if (0 != getdata((char*&)zdata.next_out, zdata.avail_out, cb,context)) {
           deflateEnd(&zdata);
           throw std::string("Can't allocate output buffer");
         }
       }
 
       while ( Z_STREAM_END != deflate(&zdata, Z_FINISH)) {
-        if (0 != getdata((char*&)zdata.next_out, zdata.avail_out, cb)) {
+        if (0 != getdata((char*&)zdata.next_out, zdata.avail_out, cb,context)) {
           deflateEnd(&zdata);
           throw std::string("Can't allocate output buffer");
         }
@@ -370,7 +370,7 @@ uint64_t Compressor::compress(char* in, unsigned size,
       sdata.avail_in = size;
       RLCOMP_init(&sdata);
 
-      if (0 != getdata(sdata.next_out, sdata.avail_out,cb)) {
+      if (0 != getdata(sdata.next_out, sdata.avail_out,cb,context)) {
         throw std::string("Can't allocate output buffer");
       }
 
@@ -378,7 +378,7 @@ uint64_t Compressor::compress(char* in, unsigned size,
       sdata.avail_out--;
 
       while (!RLCOMP_compress(&sdata)) {
-        if (0 != getdata(sdata.next_out, sdata.avail_out,cb)) {
+        if (0 != getdata(sdata.next_out, sdata.avail_out,cb,context)) {
           throw std::string("Can't allocate output buffer");
         }
       }
@@ -395,7 +395,7 @@ uint64_t Compressor::compress(char* in, unsigned size,
 
 // Decompress in one of three ways
 uint64_t Compressor::decompress(char *in, unsigned size, 
-                                OutputDataCallback* cb) {
+                                OutputDataCallback* cb, void* context) {
   assert(in && "Can't decompress null buffer");
   assert(size > 1 && "Can't decompress empty buffer");
   assert(cb && "Can't decompress without a callback function");
@@ -426,7 +426,7 @@ uint64_t Compressor::decompress(char *in, unsigned size,
       }
 
       // Get a block of memory
-      if (0 != getdata(bzdata.next_out, bzdata.avail_out,cb)) {
+      if (0 != getdata(bzdata.next_out, bzdata.avail_out,cb,context)) {
         BZ2_bzDecompressEnd(&bzdata);
         throw std::string("Can't allocate output buffer");
       }
@@ -434,7 +434,7 @@ uint64_t Compressor::decompress(char *in, unsigned size,
       // Decompress it
       int bzerr = BZ_OK;
       while (BZ_OK == (bzerr = BZ2_bzDecompress(&bzdata))) {
-        if (0 != getdata(bzdata.next_out, bzdata.avail_out,cb)) {
+        if (0 != getdata(bzdata.next_out, bzdata.avail_out,cb,context)) {
           BZ2_bzDecompressEnd(&bzdata);
           throw std::string("Can't allocate output buffer");
         }
@@ -471,14 +471,14 @@ uint64_t Compressor::decompress(char *in, unsigned size,
       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)) {
+      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)) {
+        if (0 != getdata((char*&)zdata.next_out, zdata.avail_out,cb,context)) {
           inflateEnd(&zdata);
           throw std::string("Can't allocate output buffer");
         }
@@ -499,12 +499,12 @@ uint64_t Compressor::decompress(char *in, unsigned size,
       sdata.avail_in = size - 1;
       RLCOMP_init(&sdata);
 
-      if (0 != getdata(sdata.next_out, sdata.avail_out,cb)) {
+      if (0 != getdata(sdata.next_out, sdata.avail_out,cb,context)) {
         throw std::string("Can't allocate output buffer");
       }
 
       while (!RLCOMP_decompress(&sdata)) {
-        if (0 != getdata(sdata.next_out, sdata.avail_out,cb)) {
+        if (0 != getdata(sdata.next_out, sdata.avail_out,cb,context)) {
           throw std::string("Can't allocate output buffer");
         }
       }