Change FlateCompress() to use spans
Pass 2 spans instead of 2 pairs of points and sizes. Internalize the
conversion from size_t to unsigned long and back. Also get rid of the
in-out parameter by returning the compressed size.
Change-Id: I66b57b8ae86dbdad4a5dfd3becbd6c82b74573f2
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/119231
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Thomas Sepez <tsepez@google.com>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/core/fxcodec/flate/flatemodule.cpp b/core/fxcodec/flate/flatemodule.cpp
index 7aa3b15..2bdf723 100644
--- a/core/fxcodec/flate/flatemodule.cpp
+++ b/core/fxcodec/flate/flatemodule.cpp
@@ -69,11 +69,15 @@
return pdfium::saturated_cast<uint32_t>(context->total_in);
}
-bool FlateCompress(unsigned char* dest_buf,
- unsigned long* dest_size,
- const unsigned char* src_buf,
- unsigned long src_size) {
- return compress(dest_buf, dest_size, src_buf, src_size) == Z_OK;
+size_t FlateCompress(pdfium::span<const uint8_t> src_span,
+ pdfium::span<uint8_t> dest_span) {
+ const auto src_size = pdfium::checked_cast<unsigned long>(src_span.size());
+ auto dest_size = pdfium::checked_cast<unsigned long>(dest_span.size());
+ if (compress(dest_span.data(), &dest_size, src_span.data(), src_size) !=
+ Z_OK) {
+ return 0;
+ }
+ return pdfium::checked_cast<size_t>(dest_size);
}
z_stream* FlateInit() {
@@ -890,17 +894,12 @@
// static
DataVector<uint8_t> FlateModule::Encode(pdfium::span<const uint8_t> src_span) {
- const unsigned long src_size =
- pdfium::checked_cast<unsigned long>(src_span.size());
- pdfium::CheckedNumeric<unsigned long> safe_dest_size = src_size;
- safe_dest_size += src_size / 1000;
+ FX_SAFE_SIZE_T safe_dest_size = src_span.size();
+ safe_dest_size += src_span.size() / 1000;
safe_dest_size += 12;
- unsigned long dest_size = safe_dest_size.ValueOrDie();
- DataVector<uint8_t> dest_buf(dest_size);
- if (!FlateCompress(dest_buf.data(), &dest_size, src_span.data(), src_size))
- return {};
-
- dest_buf.resize(pdfium::checked_cast<size_t>(dest_size));
+ DataVector<uint8_t> dest_buf(safe_dest_size.ValueOrDie());
+ size_t compressed_size = FlateCompress(src_span, dest_buf);
+ dest_buf.resize(compressed_size);
return dest_buf;
}
