Repo created

libs/coding/sha1.cpp

@@ -0,0 +1,77 @@
+#include "coding/sha1.hpp"
+#include "coding/base64.hpp"
+
+#include "coding/internal/file_data.hpp"
+#include "coding/reader.hpp"
+
+#include "base/assert.hpp"
+#include "base/logging.hpp"
+
+#include <boost/uuid/detail/sha1.hpp>
+
+#include <algorithm>
+#include <vector>
+#include <bit>
+
+namespace coding
+{
+namespace
+{
+SHA1::Hash ExtractHash(boost::uuids::detail::sha1 & sha1)
+{
+  boost::uuids::detail::sha1::digest_type digest;
+  sha1.get_digest(digest);
+  for (auto & b : digest)
+    b = std::byteswap(b);
+
+  SHA1::Hash result;
+  static_assert(result.size() == sizeof(digest));
+  std::copy_n(reinterpret_cast<uint8_t const *>(digest), sizeof(digest), std::begin(result));
+  return result;
+}
+}  // namespace
+
+// static
+SHA1::Hash SHA1::Calculate(std::string const & filePath)
+{
+  try
+  {
+    base::FileData file(filePath, base::FileData::Op::READ);
+    uint64_t const fileSize = file.Size();
+
+    boost::uuids::detail::sha1 sha1;
+
+    uint64_t currSize = 0;
+    uint32_t constexpr kFileBufferSize = 8192;
+    unsigned char buffer[kFileBufferSize];
+    while (currSize < fileSize)
+    {
+      auto const toRead = std::min(kFileBufferSize, static_cast<uint32_t>(fileSize - currSize));
+      file.Read(currSize, buffer, toRead);
+      sha1.process_bytes(buffer, toRead);
+      currSize += toRead;
+    }
+    return ExtractHash(sha1);
+  }
+  catch (Reader::Exception const & ex)
+  {
+    LOG(LERROR, ("Error reading file:", filePath, ex.what()));
+  }
+  return {};
+}
+
+// static
+std::string SHA1::CalculateBase64(std::string const & filePath)
+{
+  auto const sha1 = Calculate(filePath);
+  return base64::Encode(std::string_view(reinterpret_cast<char const *>(sha1.data()), sha1.size()));
+}
+
+// static
+SHA1::Hash SHA1::CalculateForString(std::string_view str)
+{
+  boost::uuids::detail::sha1 sha1;
+  sha1.process_bytes(str.data(), str.size());
+  return ExtractHash(sha1);
+}
+}  // namespace coding