Add an API to unpack Zip files directly from and to file descriptors.

chrome/common/zip_internal.cc

Index: chrome/common/zip_internal.cc
diff --git a/chrome/common/zip_internal.cc b/chrome/common/zip_internal.cc
index ddcfd00a360fb1d01383d27f04aa75669e92d7f5..9d693ddd4e6c9d8b008121ea1dd15239f7c7be4f 100644
--- a/chrome/common/zip_internal.cc
+++ b/chrome/common/zip_internal.cc
@@ -9,6 +9,8 @@
 #include "third_party/zlib/contrib/minizip/zip.h"
 #if defined(OS_WIN)
 #include "third_party/zlib/contrib/minizip/iowin32.h"
+#elif defined(OS_POSIX)
+#include "third_party/zlib/contrib/minizip/ioapi.h"
 #endif
 
 namespace {
@@ -65,6 +67,42 @@ void* ZipOpenFunc(void *opaque, const char* filename, int mode) {
 }
 #endif
 
+#if defined(OS_POSIX)
+void* fdopen_file_func(void* opaque, const char* filename, int mode) {

[satorux1, 2011/12/15 00:05:36]

Since the code is now in Chrome codebase, the function name should look like
FdOpenFileFunc?

[Jorge Lucangeli Obes, 2011/12/15 00:19:00]

Done.

+    FILE* file = NULL;

[satorux1, 2011/12/15 00:05:36]

And the indentation is 2, instead of 4.

[Jorge Lucangeli Obes, 2011/12/15 00:19:00]

Done.

+    const char* mode_fopen = NULL;
+
+    if ((mode & ZLIB_FILEFUNC_MODE_READWRITEFILTER) == ZLIB_FILEFUNC_MODE_READ)
+        mode_fopen = "rb";
+    else if (mode & ZLIB_FILEFUNC_MODE_EXISTING)
+        mode_fopen = "r+b";
+    else if (mode & ZLIB_FILEFUNC_MODE_CREATE)
+        mode_fopen = "wb";
+
+    if ((filename != NULL) && (mode_fopen != NULL))
+        file = fdopen(*static_cast<int*>(opaque), mode_fopen);
+
+    return file;
+}
+
+// We don't actually close the file stream since that would close
+// the underlying file descriptor, and we don't own it. We do free
+// |opaque| since we malloc'ed in fill_fdopen_filefunc.
+int fclose_file_func(void* opaque, void* stream) {
+    free(opaque);
+    return 0;
+}
+
+void fill_fdopen_filefunc(zlib_filefunc_def* pzlib_filefunc_def, int fd) {
+    fill_fopen_filefunc(pzlib_filefunc_def);
+    pzlib_filefunc_def->zopen_file = fdopen_file_func;
+    pzlib_filefunc_def->zclose_file = fclose_file_func;
+    int* ptr_fd = static_cast<int*>(malloc(sizeof(fd)));
+    *ptr_fd = fd;
+    pzlib_filefunc_def->opaque = ptr_fd;
+}
+#endif  // defined(OS_POSIX)
+
 }  // namespace
 
 namespace zip {
@@ -81,6 +119,15 @@ unzFile OpenForUnzipping(const std::string& file_name_utf8) {
   return unzOpen2(file_name_utf8.c_str(), zip_func_ptrs);
 }
 
+#if defined(OS_POSIX)
+unzFile OpenFdForUnzipping(int zip_fd) {
+  zlib_filefunc_def zip_funcs;
+  fill_fdopen_filefunc(&zip_funcs, zip_fd);
+  // Passing dummy "fd" filename to zlib.
+  return unzOpen2("fd", &zip_funcs);
+}
+#endif
+
 zipFile OpenForZipping(const std::string& file_name_utf8, int append_flag) {
   zlib_filefunc_def* zip_func_ptrs = NULL;
 #if defined(OS_WIN)