From 4fc02aa41f476db06d057ab7462a4bc1aa38ca29 Mon Sep 17 00:00:00 2001
From: Ivan Dlugos <6349682+vaind@users.noreply.github.com>
Date: Tue, 7 Feb 2023 15:12:10 +0100
Subject: [PATCH] feat: PE embedded PPDB decompression to a custom writer
 (#757)

---
 CHANGELOG.md                             |  2 +-
 symbolic-debuginfo/src/pe.rs             | 23 ++++++++++-------------
 symbolic-debuginfo/tests/test_objects.rs | 10 ++++++++--
 symbolic-ppdb/tests/test_ppdb.rs         |  6 ++++--
 4 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5ad99cde8..79acefb99 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,7 +6,7 @@
 
 - Correctly read the `debug_id` of Deterministic PE files ([#658](https://github.com/getsentry/symbolic/pull/658))
 - Gracefully handle invalid PPDBs ([#751](https://github.com/getsentry/symbolic/pull/751))
-- Support embedded PortablePDB in DLLs ([#752](https://github.com/getsentry/symbolic/pull/752))
+- Support embedded PortablePDB in DLLs ([#752](https://github.com/getsentry/symbolic/pull/752), [#757](https://github.com/getsentry/symbolic/pull/757))
 
 ## 11.0.0
 
diff --git a/symbolic-debuginfo/src/pe.rs b/symbolic-debuginfo/src/pe.rs
index 8cf4d7f21..31a6995a1 100644
--- a/symbolic-debuginfo/src/pe.rs
+++ b/symbolic-debuginfo/src/pe.rs
@@ -3,9 +3,8 @@
 use std::borrow::Cow;
 use std::error::Error;
 use std::fmt;
-use std::io::Read;
+use std::io::Write;
 
-use flate2::read::DeflateDecoder;
 use gimli::RunTimeEndian;
 use goblin::pe;
 use scroll::{Pread, LE};
@@ -504,16 +503,14 @@ impl<'data, 'object> PeEmbeddedPortablePDB<'data> {
         self.uncompressed_size
     }
 
-    /// Reads the Portable PDB contents into the provided vector.
-    pub fn decompress(&self) -> Result<Vec<u8>, PeError> {
-        let mut decoder = DeflateDecoder::new(self.compressed_data);
-        let mut output: Vec<u8> = vec![0; self.uncompressed_size];
-        let read_size = decoder.read(&mut output).map_err(PeError::new)?;
-        if read_size != self.uncompressed_size {
-            return Err(PeError::new(symbolic_ppdb::FormatError::from(
-                symbolic_ppdb::FormatErrorKind::InvalidLength,
-            )));
-        }
-        Ok(output)
+    /// Reads the Portable PDB contents into the writer.
+    pub fn decompress_to<W: Write>(&self, output: W) -> Result<(), PeError> {
+        use std::io::prelude::*;
+        let mut decoder = flate2::write::DeflateDecoder::new(output);
+        decoder
+            .write_all(self.compressed_data)
+            .and_then(|_| decoder.finish())
+            .map_err(PeError::new)?;
+        Ok(())
     }
 }
diff --git a/symbolic-debuginfo/tests/test_objects.rs b/symbolic-debuginfo/tests/test_objects.rs
index d34460585..dcfd3797c 100644
--- a/symbolic-debuginfo/tests/test_objects.rs
+++ b/symbolic-debuginfo/tests/test_objects.rs
@@ -1,4 +1,4 @@
-use std::{ffi::CString, fmt};
+use std::{env, ffi::CString, fmt, io::BufWriter};
 
 use symbolic_common::ByteView;
 use symbolic_debuginfo::{
@@ -565,8 +565,14 @@ fn test_pe_embedded_ppdb() -> Result<(), Error> {
         let embedded_ppdb = pe.embedded_ppdb().unwrap().unwrap();
         assert_eq!(embedded_ppdb.get_size(), 10540);
 
-        let buf = embedded_ppdb.decompress()?;
+        let mut buf = Vec::new();
+        embedded_ppdb.decompress_to(&mut buf)?;
         assert_eq!(&buf[15..25], "\0PDB v1.0\0".as_bytes());
+
+        let tmp_file = tempfile::tempfile()?;
+        embedded_ppdb.decompress_to(BufWriter::new(&tmp_file))?;
+        let file_buf = ByteView::map_file(tmp_file)?;
+        assert_eq!(buf, file_buf.as_slice());
     }
     Ok(())
 }
diff --git a/symbolic-ppdb/tests/test_ppdb.rs b/symbolic-ppdb/tests/test_ppdb.rs
index a3b5c0903..1e5e6da47 100644
--- a/symbolic-ppdb/tests/test_ppdb.rs
+++ b/symbolic-ppdb/tests/test_ppdb.rs
@@ -109,7 +109,8 @@ fn test_pe_embedded_ppdb_without_sources() {
     let pe = PeObject::parse(&pe_buf).unwrap();
 
     let embedded_ppdb = pe.embedded_ppdb().unwrap().unwrap();
-    let ppdb_buf = embedded_ppdb.decompress().unwrap();
+    let mut ppdb_buf = Vec::new();
+    embedded_ppdb.decompress_to(&mut ppdb_buf).unwrap();
     let ppdb = PortablePdb::parse(&ppdb_buf).unwrap();
 
     assert_eq!(ppdb.pdb_id().unwrap(), pe.debug_id());
@@ -128,7 +129,8 @@ fn test_pe_embedded_ppdb_with_sources() {
     let pe = PeObject::parse(&pe_buf).unwrap();
 
     let embedded_ppdb = pe.embedded_ppdb().unwrap().unwrap();
-    let ppdb_buf = embedded_ppdb.decompress().unwrap();
+    let mut ppdb_buf = Vec::new();
+    embedded_ppdb.decompress_to(&mut ppdb_buf).unwrap();
     let ppdb = PortablePdb::parse(&ppdb_buf).unwrap();
 
     assert_eq!(ppdb.pdb_id().unwrap(), pe.debug_id());