Add CRC-32 computation to third_party/ijar:zipper

This can be a problem for some usage of the produced ZIP file
to not compute the CRC-32 correctly. We still skip it for ijar
for speed.

--
MOS_MIGRATED_REVID=102844157

3 files changed, 31 insertions, 12 deletions

diff --git a/third_party/ijar/zip.cc b/third_party/ijar/zip.cc
index cb9d1cc9d7..51e308de7d 100644
--- a/third_party/ijar/zip.cc
+++ b/third_party/ijar/zip.cc
@@ -213,7 +213,8 @@ class OutputZipFile : public ZipBuilder {
 
   virtual ~OutputZipFile() { Finish(); }
   virtual u1* NewFile(const char* filename, const u4 attr);
-  virtual int FinishFile(size_t filelength, bool compress = false);
+  virtual int FinishFile(size_t filelength, bool compress = false,
+                         bool compute_crc = false);
   virtual int WriteEmptyFile(const char *filename);
   virtual size_t GetSize() {
     return Offset(q);
@@ -235,6 +236,9 @@ class OutputZipFile : public ZipBuilder {
     // Compression method
     u2 compression_method;
 
+    // CRC32
+    u4 crc32;
+
     // external attributes field
     u4 external_attr;
 
@@ -289,8 +293,10 @@ class OutputZipFile : public ZipBuilder {
 
   // Fill in the "compressed size" and "uncompressed size" fields in a local
   // file header previously written by WriteLocalFileHeader().
-  size_t WriteFileSizeInLocalFileHeader(u1 *header_ptr, size_t out_length,
-                                        bool compress = false);
+  size_t WriteFileSizeInLocalFileHeader(u1 *header_ptr,
+                                        size_t out_length,
+                                        bool compress = false,
+                                        const u4 crc = 0);
 };
 
 //
@@ -760,6 +766,7 @@ int OutputZipFile::WriteEmptyFile(const char *filename) {
   LocalFileEntry *entry = new LocalFileEntry;
   entry->local_header_offset = Offset(q);
   entry->external_attr = 0;
+  entry->crc32 = 0;
 
   // Output the ZIP local_file_header:
   put_u4le(q, LOCAL_FILE_HEADER_SIGNATURE);
@@ -768,7 +775,7 @@ int OutputZipFile::WriteEmptyFile(const char *filename) {
   put_u2le(q, 0);  // compression_method
   put_u2le(q, 0);  // last_mod_file_time
   put_u2le(q, 0);  // last_mod_file_date
-  put_u4le(q, 0);  // crc32
+  put_u4le(q, entry->crc32);  // crc32
   put_u4le(q, 0);  // compressed_size
   put_u4le(q, 0);  // uncompressed_size
   put_u2le(q, file_name_length);
@@ -800,7 +807,7 @@ void OutputZipFile::WriteCentralDirectory() {
     put_u2le(q, entry->compression_method);  // compression method:
     put_u2le(q, 0);                          // last_mod_file_time
     put_u2le(q, 0);  // last_mod_file_date
-    put_u4le(q, 0);  // crc32 (jar/javac tools don't care)
+    put_u4le(q, entry->crc32);  // crc32
     put_u4le(q, entry->compressed_length);    // compressed_size
     put_u4le(q, entry->uncompressed_length);  // uncompressed_size
     put_u2le(q, entry->file_name_length);
@@ -848,7 +855,7 @@ u1* OutputZipFile::WriteLocalFileHeader(const char* filename, const u4 attr) {
   put_u2le(q, COMPRESSION_METHOD_STORED);  // compression method = placeholder
   put_u2le(q, 0);                          // last_mod_file_time
   put_u2le(q, 0);                          // last_mod_file_date
-  put_u4le(q, 0);                          // crc32 (jar/javac tools don't care)
+  put_u4le(q, entry->crc32);               // crc32
   put_u4le(q, 0);  // compressed_size = placeholder
   put_u4le(q, 0);  // uncompressed_size = placeholder
   put_u2le(q, entry->file_name_length);
@@ -901,7 +908,8 @@ size_t TryDeflate(u1 *buf, size_t length) {
 
 size_t OutputZipFile::WriteFileSizeInLocalFileHeader(u1 *header_ptr,
                                                      size_t out_length,
-                                                     bool compress) {
+                                                     bool compress,
+                                                     const u4 crc) {
   size_t compressed_size = out_length;
   if (compress) {
     compressed_size = TryDeflate(q, out_length);
@@ -912,7 +920,8 @@ size_t OutputZipFile::WriteFileSizeInLocalFileHeader(u1 *header_ptr,
   } else {
     put_u2le(header_ptr, COMPRESSION_METHOD_STORED);
   }
-  header_ptr += 8;
+  header_ptr += 4;
+  put_u4le(header_ptr, crc);              // crc32
   put_u4le(header_ptr, compressed_size);  // compressed_size
   put_u4le(header_ptr, out_length);       // uncompressed_size
   return compressed_size;
@@ -937,9 +946,15 @@ u1* OutputZipFile::NewFile(const char* filename, const u4 attr) {
   return q;
 }
 
-int OutputZipFile::FinishFile(size_t filelength, bool compress) {
+int OutputZipFile::FinishFile(size_t filelength, bool compress,
+                              bool compute_crc) {
+  u4 crc = 0;
+  if (compute_crc) {
+    crc = crc32(crc, q, filelength);
+  }
   size_t compressed_size =
-      WriteFileSizeInLocalFileHeader(header_ptr, filelength, compress);
+      WriteFileSizeInLocalFileHeader(header_ptr, filelength, compress, crc);
+  entries_.back()->crc32 = crc;
   entries_.back()->compressed_length = compressed_size;
   entries_.back()->uncompressed_length = filelength;
   if (compressed_size < filelength) {
diff --git a/third_party/ijar/zip.h b/third_party/ijar/zip.h
index c548cb3cdb..54a7a7c71c 100644
--- a/third_party/ijar/zip.h
+++ b/third_party/ijar/zip.h
@@ -63,8 +63,12 @@ class ZipBuilder {
   // Finish writing a file and specify its length. After calling this method
   // one should not reuse the pointer given by NewFile. The file can be
   // compressed using the deflate algorithm by setting `compress` to true.
+  // By default, CRC32 are not computed as java tooling doesn't care, but
+  // computing it can be activated by setting `compute_crc` to true.
   // On failure, returns -1 and GetError() will return an non-empty message.
-  virtual int FinishFile(size_t filelength, bool compress = false) = 0;
+  virtual int FinishFile(size_t filelength,
+                         bool compress = false,
+                         bool compute_crc = false) = 0;
 
   // Write an empty file, it is equivalent to:
   //   NewFile(filename, 0);
diff --git a/third_party/ijar/zip_main.cc b/third_party/ijar/zip_main.cc
index 43b035ad97..4715032060 100644
--- a/third_party/ijar/zip_main.cc
+++ b/third_party/ijar/zip_main.cc
@@ -237,7 +237,7 @@ int create(char *zipfile, char **files, bool flatten, bool verbose,
       }
       memcpy(buffer, data, statst.st_size);
       munmap(data, statst.st_size);
-      builder->FinishFile(statst.st_size, compress);
+      builder->FinishFile(statst.st_size, compress, true);
     }
   }
   if (builder->Finish() < 0) {