Introduce FileSystem::CalculateMD5AsString that supports any platform and make existing FileSystem::CalculateMD5 to use it.

http://reviews.llvm.org/D7771

llvm-svn: 230036

lldb/source/Host/common/FileSystem.cpp

@@ -0,0 +1,72 @@
+//===-- FileSystem.cpp ------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Host/FileSystem.h"
+
+#include "llvm/Support/MD5.h"
+
+#include <fstream>
+#include <vector>
+
+using namespace lldb;
+using namespace lldb_private;
+
+namespace {
+
+bool
+CalcMD5(const FileSpec &file_spec, llvm::MD5::MD5Result &md5_result)
+{
+    llvm::MD5 md5_hash;
+    std::ifstream file(file_spec.GetPath(), std::ios::binary);
+    if (!file.is_open())
+        return false;
+
+    std::vector<char> read_buf(4096);
+    while (!file.eof())
+    {
+        file.read(&read_buf[0], read_buf.size());
+        const auto read_bytes = file.gcount();
+        if (read_bytes == 0)
+            break;
+
+        md5_hash.update(llvm::StringRef(&read_buf[0], read_bytes));
+    }
+
+    md5_hash.final(md5_result);
+    return true;
+}
+
+}  // namespace
+
+bool
+FileSystem::CalculateMD5(const FileSpec &file_spec, uint64_t &low, uint64_t &high)
+{
+    llvm::MD5::MD5Result md5_result;
+    if (!CalcMD5(file_spec, md5_result))
+        return false;
+
+    const auto uint64_res = reinterpret_cast<const uint64_t*>(md5_result);
+    high = uint64_res[0];
+    low = uint64_res[1];
+
+    return true;
+}
+
+bool
+FileSystem::CalculateMD5AsString(const FileSpec &file_spec, std::string& digest_str)
+{
+    llvm::MD5::MD5Result md5_result;
+    if (!CalcMD5(file_spec, md5_result))
+        return false;
+
+    llvm::SmallString<32> result_str;
+    llvm::MD5::stringifyResult(md5_result, result_str);
+    digest_str = result_str.c_str();
+    return true;
+}