From 39c7f05ea96bea83f97d3b80056046314b7f27c8 Mon Sep 17 00:00:00 2001
From: Vikram Rajkumar <vikram@bitshares.org>
Date: Wed, 2 Jul 2014 23:28:08 -0400
Subject: [PATCH] Implement LZMA file decompression

---
 .gitignore                                    |  5 +-
 CMakeLists.txt                                |  4 +-
 include/fc/compress/lzma.hpp                  |  7 ++-
 src/compress/lzma.cpp                         | 56 +++++++++----------
 .../{lzma_compress_file.cpp => lzma_test.cpp} |  9 +--
 5 files changed, 44 insertions(+), 37 deletions(-)
 rename tests/{lzma_compress_file.cpp => lzma_test.cpp} (59%)

diff --git a/.gitignore b/.gitignore
index 0a8ee06..e956fca 100644
--- a/.gitignore
+++ b/.gitignore
@@ -33,9 +33,11 @@ ZERO_CHECK
 Debug/
 Release/
 
+CMakeCache.txt
 CMakeFiles
 Makefile
-cmake_install.cmake
+*.cmake
+
 libfc.a
 libfc_debug.a
 
@@ -45,6 +47,7 @@ fc_automoc.cpp
 git_revision.cpp
 GitSHA3.cpp
 
+lzma_test
 ntp_test
 task_cancel_test
 udt_client
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6775d43..78812b9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -237,8 +237,8 @@ target_link_libraries( udt_server fc udt )
 add_executable( udt_client tests/udtc.cpp )
 target_link_libraries( udt_client fc udt )
 
-add_executable( lzma_compress_file tests/lzma_compress_file.cpp )
-target_link_libraries( lzma_compress_file fc )
+add_executable( lzma_test tests/lzma_test.cpp )
+target_link_libraries( lzma_test fc )
 
 #add_executable( test_compress tests/compress.cpp )
 #target_link_libraries( test_compress fc )
diff --git a/include/fc/compress/lzma.hpp b/include/fc/compress/lzma.hpp
index e1b411c..44d17b7 100644
--- a/include/fc/compress/lzma.hpp
+++ b/include/fc/compress/lzma.hpp
@@ -8,9 +8,12 @@ namespace fc {
 std::vector<char> lzma_compress( const std::vector<char>& in );
 std::vector<char> lzma_decompress( const std::vector<char>& compressed );
 
-void lzma_compress_file( path src_path,
-                         path dst_path,
+void lzma_compress_file( const path& src_path,
+                         const path& dst_path,
                          unsigned char level = 5,
                          unsigned int dict_size = (1 << 20) );
 
+void lzma_decompress_file( const path& src_path,
+                           const path& dst_path );
+
 } // namespace fc
diff --git a/src/compress/lzma.cpp b/src/compress/lzma.cpp
index 91d5475..21ad80c 100644
--- a/src/compress/lzma.cpp
+++ b/src/compress/lzma.cpp
@@ -1,15 +1,8 @@
+#include <boost/iostreams/device/mapped_file.hpp>
 #include <fc/compress/lzma.hpp>
 #include <fc/exception/exception.hpp>
-
-#include <lzma_c.h>
-
-#include <boost/iostreams/device/mapped_file.hpp>
-
 #include <fstream>
-
-
-
-#include <iostream>
+#include <lzma_c.h>
 
 namespace fc {
 
@@ -120,8 +113,8 @@ static size_t output_callback( void* output_ctx, const void* output_buf, size_t
     return output_len;
 }
 
-void lzma_compress_file( path src_path,
-                         path dst_path,
+void lzma_compress_file( const path& src_path,
+                         const path& dst_path,
                          unsigned char level,
                          unsigned int dict_size )
 {
@@ -170,29 +163,36 @@ void lzma_compress_file( path src_path,
 
     elzma_compress_free( &handle );
     FC_ASSERT( rc == ELZMA_E_OK );
+}
 
+void lzma_decompress_file( const path& src_path,
+                           const path& dst_path )
+{
+    FC_ASSERT( exists( src_path ) );
+    FC_ASSERT( !exists( dst_path ) );
 
-    /* TEST */
-    FC_ASSERT( exists( dst_path ) );
+    boost::iostreams::mapped_file_source src_file;
+    src_file.open( src_path.string() );
+    FC_ASSERT( src_file.is_open() );
 
-    boost::iostreams::mapped_file_source dst_file;
-    dst_file.open( dst_path.string() );
-    FC_ASSERT( dst_file.is_open() );
+    elzma_decompress_handle handle = NULL;
+    handle = elzma_decompress_alloc();
+    FC_ASSERT( handle != NULL );
 
-    std::vector<char> result( dst_file.data(), dst_file.data() + dst_file.size() );
-    dst_file.close();
+    struct lzma_file_ctx ctx;
+    ctx.src_buf = ( const unsigned char* )src_file.data();
+    ctx.src_len = src_file.size();
+    ctx.dst_path = dst_path;
 
-    for( const auto& c : result )
-    {
-        std::cout << c;
-    }
-    std::cout << "\n";
+    auto rc = elzma_decompress_run( handle,
+                                    input_callback,
+                                    ( void * )&ctx,
+                                    output_callback,
+                                    ( void * )&ctx,
+                                    elzma_file_format::ELZMA_lzma );
 
-    result = lzma_decompress( result );
-    for( const auto& c : result )
-    {
-        std::cout << c;
-    }
+    elzma_decompress_free( &handle );
+    FC_ASSERT( rc == ELZMA_E_OK );
 }
 
 } // namespace fc
diff --git a/tests/lzma_compress_file.cpp b/tests/lzma_test.cpp
similarity index 59%
rename from tests/lzma_compress_file.cpp
rename to tests/lzma_test.cpp
index 3f76733..3457597 100644
--- a/tests/lzma_compress_file.cpp
+++ b/tests/lzma_test.cpp
@@ -8,16 +8,17 @@ using namespace fc;
 
 int main( int argc, char** argv )
 {
-    if( argc != 2 && argc != 3 )
+    if( argc != 2 )
     {
-        std::cout << "usage: " << argv[0] << " <src_path> [dst_path = src_path.lzma]\n";
+        std::cout << "usage: " << argv[0] << " <filename>\n";
         exit( -1 );
     }
 
     auto src = std::string( argv[1] );
-    auto dst = (argc == 3) ? std::string( argv[2] ) : src + ".lzma";
-
+    auto dst = src + ".compressed";
     lzma_compress_file( src, dst );
 
+    lzma_decompress_file( dst, src + ".decompressed" );
+
     return 0;
 }