1 files changed, 223 insertions, 0 deletions
diff --git a/source/core/StarCompression.cpp b/source/core/StarCompression.cpp
new file mode 100644
index 0000000..e8d282c
--- /dev/null
+++ b/source/core/StarCompression.cpp
@@ -0,0 +1,223 @@
+#include "StarCompression.hpp"
+#include "StarFormat.hpp"
+#include "StarLexicalCast.hpp"
+
+#include <zlib.h>
+#include <errno.h>
+#include <string.h>
+
+namespace Star {
+
+void compressData(ByteArray const& in, ByteArray& out, CompressionLevel compression) {
+  out.clear();
+
+  if (in.empty())
+    return;
+
+  const size_t BUFSIZE = 32 * 1024;
+  unsigned char temp_buffer[BUFSIZE];
+
+  z_stream strm;
+  strm.zalloc = Z_NULL;
+  strm.zfree = Z_NULL;
+  strm.opaque = Z_NULL;
+  int deflate_res = deflateInit(&strm, compression);
+  if (deflate_res != Z_OK)
+    throw IOException(strf("Failed to initialise deflate (%d)", deflate_res));
+
+  strm.next_in = (unsigned char*)in.ptr();
+  strm.avail_in = in.size();
+  strm.next_out = temp_buffer;
+  strm.avail_out = BUFSIZE;
+  while (deflate_res == Z_OK) {
+    deflate_res = deflate(&strm, Z_FINISH);
+    if (strm.avail_out == 0) {
+      out.append((char const*)temp_buffer, BUFSIZE);
+      strm.next_out = temp_buffer;
+      strm.avail_out = BUFSIZE;
+    }
+  }
+  deflateEnd(&strm);
+
+  if (deflate_res != Z_STREAM_END)
+    throw IOException(strf("Internal error in uncompressData, deflate_res is %s", deflate_res));
+
+  out.append((char const*)temp_buffer, BUFSIZE - strm.avail_out);
+}
+
+ByteArray compressData(ByteArray const& in, CompressionLevel compression) {
+  ByteArray out = ByteArray::withReserve(in.size());
+  compressData(in, out, compression);
+  return out;
+}
+
+void uncompressData(ByteArray const& in, ByteArray& out) {
+  out.clear();
+
+  if (in.empty())
+    return;
+
+  const size_t BUFSIZE = 32 * 1024;
+  unsigned char temp_buffer[BUFSIZE];
+
+  z_stream strm;
+  strm.zalloc = Z_NULL;
+  strm.zfree = Z_NULL;
+  strm.opaque = Z_NULL;
+  int inflate_res = inflateInit(&strm);
+  if (inflate_res != Z_OK)
+    throw IOException(strf("Failed to initialise inflate (%d)", inflate_res));
+
+  strm.next_in = (unsigned char*)in.ptr();
+  strm.avail_in = in.size();
+  strm.next_out = temp_buffer;
+  strm.avail_out = BUFSIZE;
+
+  while (inflate_res == Z_OK || inflate_res == Z_BUF_ERROR) {
+    inflate_res = inflate(&strm, Z_FINISH);
+    if (strm.avail_out == 0) {
+      out.append((char const*)temp_buffer, BUFSIZE);
+      strm.next_out = temp_buffer;
+      strm.avail_out = BUFSIZE;
+    } else if (inflate_res == Z_BUF_ERROR) {
+      break;
+    }
+  }
+  inflateEnd(&strm);
+
+  if (inflate_res != Z_STREAM_END)
+    throw IOException(strf("Internal error in uncompressData, inflate_res is %s", inflate_res));
+
+  out.append((char const*)temp_buffer, BUFSIZE - strm.avail_out);
+}
+
+ByteArray uncompressData(ByteArray const& in) {
+  ByteArray out = ByteArray::withReserve(in.size());
+  uncompressData(in, out);
+  return out;
+}
+
+CompressedFilePtr CompressedFile::open(String const& filename, IOMode mode, CompressionLevel comp) {
+  CompressedFilePtr f = make_shared<CompressedFile>(filename);
+  f->open(mode, comp);
+  return f;
+}
+
+CompressedFile::CompressedFile()
+  : IODevice(IOMode::Closed), m_file(0), m_compression(MediumCompression) {}
+
+CompressedFile::CompressedFile(String filename)
+  : IODevice(IOMode::Closed), m_file(0), m_compression(MediumCompression) {
+  setFilename(move(filename));
+}
+
+CompressedFile::~CompressedFile() {
+  close();
+}
+
+StreamOffset CompressedFile::pos() {
+  return gztell((gzFile)m_file);
+}
+
+void CompressedFile::seek(StreamOffset offset, IOSeek seekMode) {
+  StreamOffset begPos = pos();
+
+  int retCode;
+  if (seekMode == IOSeek::Relative) {
+    retCode = gzseek((gzFile)m_file, (z_off_t)offset, SEEK_CUR);
+  } else if (seekMode == IOSeek::Absolute) {
+    retCode = gzseek((gzFile)m_file, (z_off_t)offset, SEEK_SET);
+  } else {
+    throw IOException("Cannot seek with SeekEnd in compressed file");
+  }
+
+  StreamOffset endPos = pos();
+
+  if (retCode < 0) {
+    throw IOException::format("Seek error: %s", gzerror((gzFile)m_file, 0));
+  } else if ((seekMode == IOSeek::Relative && begPos + offset != endPos)
+      || (seekMode == IOSeek::Absolute && offset != endPos)) {
+    throw EofException("Error, unexpected end of file found");
+  }
+}
+
+bool CompressedFile::atEnd() {
+  return gzeof((gzFile)m_file);
+}
+
+size_t CompressedFile::read(char* data, size_t len) {
+  if (len == 0)
+    return 0;
+
+  int ret = gzread((gzFile)m_file, data, len);
+  if (ret == 0)
+    throw EofException("Error, unexpected end of file found");
+  else if (ret == -1)
+    throw IOException::format("Read error: %s", gzerror((gzFile)m_file, 0));
+  else
+    return (size_t)ret;
+}
+
+size_t CompressedFile::write(const char* data, size_t len) {
+  if (len == 0)
+    return 0;
+
+  int ret = gzwrite((gzFile)m_file, data, len);
+  if (ret == 0)
+    throw IOException::format("Write error: %s", gzerror((gzFile)m_file, 0));
+  else
+    return (size_t)ret;
+}
+
+void CompressedFile::setFilename(String filename) {
+  if (isOpen())
+    throw IOException("Cannot call setFilename while CompressedFile is open");
+  m_filename = move(filename);
+}
+
+void CompressedFile::setCompression(CompressionLevel compression) {
+  if (isOpen())
+    throw IOException("Cannot call setCompression while CompressedFile is open");
+  m_compression = compression;
+}
+
+void CompressedFile::open(IOMode mode, CompressionLevel compression) {
+  close();
+  setCompression(compression);
+  open(mode);
+}
+
+void CompressedFile::sync() {
+  gzflush((gzFile)m_file, Z_FULL_FLUSH);
+}
+
+void CompressedFile::open(IOMode mode) {
+  setMode(mode);
+  String modeString;
+
+  if (mode & IOMode::Append) {
+    throw IOException("CompressedFile not compatible with Append mode");
+  } else if ((mode & IOMode::Read) && (mode & IOMode::Write)) {
+    throw IOException("CompressedFile not compatible with ReadWrite mode");
+  } else if (mode & IOMode::Write) {
+    modeString = "wb";
+  } else if (mode & IOMode::Read) {
+    modeString = "rb";
+  }
+
+  modeString += toString(m_compression);
+
+  m_file = gzopen(m_filename.utf8Ptr(), modeString.utf8Ptr());
+
+  if (!m_file)
+    throw IOException::format("Cannot open filename '%s'", m_filename);
+}
+
+void CompressedFile::close() {
+  if (m_file)
+    gzclose((gzFile)m_file);
+  m_file = 0;
+  setMode(IOMode::Closed);
+}
+
+}