reg2bin: Shrink output by reusing common strings

...all the "Offset of Idx-Name" in the data format can likely be further shrunk
by getting rid of the newly added level of indirection again.

Change-Id: I322f4869a4d6f2e63802406f998e22beea30db41

1 files changed, 13 insertions, 3 deletions

diff --git a/registry/tools/reg2bin.cxx b/registry/tools/reg2bin.cxx
index 7e5001e05d26..d10ad2a13b9c 100644
--- a/registry/tools/reg2bin.cxx
+++ b/registry/tools/reg2bin.cxx
@@ -974,9 +974,19 @@ sal_uInt64 writeNameNul(osl::File & file, rtl::OUString const & name) {
 }
 
 void writeNameLen(osl::File & file, rtl::OUString const & name) {
-    rtl::OString ascii(toAscii(name));
-    write32(file, ascii.getLength());
-    write(file, ascii.getStr(), ascii.getLength());
+    static std::map< rtl::OUString, sal_uInt64 > reuse;
+    std::map< rtl::OUString, sal_uInt64 >::iterator i(reuse.find(name));
+    if (i == reuse.end()) {
+        reuse.insert(std::make_pair(name, getOffset(file)));
+        rtl::OString ascii(toAscii(name));
+        assert(
+            (static_cast< sal_uInt64 >(ascii.getLength()) & 0x80000000) == 0);
+        write32(
+            file, static_cast< sal_uInt64 >(ascii.getLength()) | 0x80000000);
+        write(file, ascii.getStr(), ascii.getLength());
+    } else {
+        write32(file, i->second);
+    }
 }
 
 void writeType(osl::File & file, Item const & item, bool flag = false) {