求助：如何让gorocks支持lz4

[guileen]

我阅读了qdb的代码后发现，qdb强制使用 Lz4 作为rocksdb的压缩策略。但我实际测试中总是遇到“Invalid argument: Compression type LZ4 is not linked with the binary.” 错误。

在各种文档中包括rocksdb官方文档中，也未描述，如何在编译中加入lz4的支持，已向rocksdb提issue尚未得到解答。且与gorocks相关，可能问题会有所不同，所以只能来此求助，还望大神解答。

[siddontang]

is lz4 in system path, like /usr/local/lib? maybe youcan add lz4 lib path in LD_LIBRARY_PATH.

[guileen]

也就是说rocksdb会自动检测系统有没有lz4，来自动进行编译。

lz4在/usr/local/lib中。之前系统没有设置 LD_LIBRARY_PATH，所以可能是/usr/lib 路径。现在使用 cd extern/rocksdb && LD_LIBRARY_PATH=/usr/local/lib make -j4 install-shared 进行编译，编译成功。

但是，在编译gorocks时无法通过，哪怕没有llz4 。

    cd extern/gorocks && go clean -i ./ && LD_LIBRARY_PATH=$(LIBRARY_PATH) CGO_CFLAGS="-I$(ROCKS_INCLUDE) -I$(LZ4_INCLUDE)" CGO_LDFLAGS="-L$(ROCKS_LIB) -L$(LZ4_PATH) -L/usr/local/lib -lz -llz4" go install ./

报如信息很长，最后一段如下：

      bool std::__1::__insertion_sort_incomplete<rocksdb::(anonymous namespace)::CompareLogByPointer&, std::__1::unique_ptr<rocksdb::LogFile, std::__1::default_delete<rocksdb::LogFile> >*>(std::__1::unique_ptr<rocksdb::LogFile, std::__1::default_delete<rocksdb::LogFile> >*, std::__1::unique_ptr<rocksdb::LogFile, std::__1::default_delete<rocksdb::LogFile> >*, rocksdb::(anonymous namespace)::CompareLogByPointer&) in librocksdb.a(wal_manager.o)
  "___gxx_personality_v0", referenced from:
      _rocksdb_open in librocksdb.a(c.o)
      _rocksdb_open_for_read_only in librocksdb.a(c.o)
      _rocksdb_backup_engine_open in librocksdb.a(c.o)
      _rocksdb_backup_engine_create_new_backup in librocksdb.a(c.o)
      _rocksdb_backup_engine_restore_db_from_latest_backup in librocksdb.a(c.o)
      _rocksdb_open_column_families in librocksdb.a(c.o)
      _rocksdb_open_for_read_only_column_families in librocksdb.a(c.o)
      ...
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [install_golibs] Error 2

我的系统是mac OSX，很奇怪，现在无论我如何尝试，都无法编译gorocks了，总是报ld错误。甚至无法恢复到以前的情况。

哪怕我删掉liblz4，去掉LD_LIBRARY_PATH环境变量。

[siddontang]

LD_LIBRARY_PATH is not for mac osx, but for linux.
Btw, you should use make shared_lib to build rocksdb in mac osx, not static lib.