How to compile RocksDB for IOS? - ios

Question

I've been trying to compile the rocksdb platform for iOS for a while now.
The simple git clone the repo and run
TARGET_OS="IOS" make static_lib -j8
fails with a spew of errors, and I'm not sure where I can also add the preprocessor directives.
I have then been looking at wrappers, and trying to compile them for a later version:
https://github.com/koraykoska/rocksdb.swift : This uses a rocksdb version of 6.4.7, and uses CocoaPods to compile the rocksdb library and the swift wrapper. I have tried cloning the rocksdb repo into the upstream folder, and then use this 'rocksdb.swift' pod in an Xcode Project.
Here are the changes I made in the pod spec(v6.22.1 being the one I need to compile.)
(librocksdb.podspec)
s.name = 'librocksdb'
s.version = '***6.22.1***'
s.summary = 'rocksdb bindings for Swift. Cocoapods and SPM support. Linux support.'
(rocksdb.swift.podspec)
s.name = 'rocksdb.swift'
s.version = '***6.22.1***'
s.summary = 'rocksdb Wrapper for Swift. Cocoapods and SPM support. Linux support.'
...
s.dependency 'librocksdb', '~> ***6.22.1***'
...
The pod install now fails as it cannot find the 'new' version of librocksdb so I add both librocksdb and rocksdb.swift to my Podfile with the :path => format.
The pod then installs, and the Xcode project has this error
/.../librdb/librocksdb/rocksdb/memtable/write_buffer_manager.cc:10:10: 'rocksdb/write_buffer_manager.h' file not found
https://github.com/hlzhang/rocksdb-build : Along similar lines to the previous wrapper, I tried changing the versions and then compiling. This meant some changes in common.sh and build-rocksdb-ios.sh scripts. Fails with
monitoring/perf_context.cc:23:2: error: "No thread-local support. Disable perf context with -DNPERF_CONTEXT."
#error "No thread-local support. Disable perf context with -DNPERF_CONTEXT."
^
1 error generated.
monitoring/iostats_context.cc:19:2: error: "No thread-local support. Disable iostats context with -DNIOSTATS_CONTEXT."
#error \
^
1 error generated.
$DEBUG_LEVEL is 0
monitoring/iostats_context.cc:19:2: error: "No thread-local support. Disable iostats context with -DNIOSTATS_CONTEXT."
#error \
^
monitoring/perf_context.cc:23:2: error: "No thread-local support. Disable perf context with -DNPERF_CONTEXT."
#error "No thread-local support. Disable perf context with -DNPERF_CONTEXT."
^
1 error generated.
1 error generated.
In file included from cache/sharded_cache.cc:16:
In file included from ./util/hash.h:26:
./util/fastrange.h:60:5: error: unknown type name '__uint128_t'
__uint128_t wide = __uint128_t{range} * hash;
^
./util/fastrange.h:60:24: error: use of undeclared identifier '__uint128_t'
__uint128_t wide = __uint128_t{range} * hash;
^
./util/fastrange.h:60:35: error: expected ';' at end of declaration
__uint128_t wide = __uint128_t{range} * hash;
^
;
./util/fastrange.h:53:35: error: unused parameter 'hash' [-Werror,-Wunused-parameter]
static inline Range Fn(uint64_t hash, Range range) {
^
./util/fastrange.h:53:47: error: unused parameter 'range' [-Werror,-Wunused-parameter]
static inline Range Fn(uint64_t hash, Range range) {
^
5 errors generated.
I try adding the relevant flags to the CFLAGS variable, and also add the -std=c++17 flag to attempt to resolve the uint__128 issue.
This then fails with
./cache/lru_cache.h:269:11: error: aligned deallocation function of type 'void (void *, std::align_val_t) noexcept' is only available on iOS 11 or newer
virtual ~LRUCacheShard() override = default;
^
cache/lru_cache.cc:656:18: note: in defaulted destructor for 'rocksdb::LRUCacheShard' first required here
shards_[i].~LRUCacheShard();
^
./cache/lru_cache.h:269:11: note: if you supply your own aligned allocation functions, use -faligned-allocation to silence this diagnostic
virtual ~LRUCacheShard() override = default;
^
1 error generated.
This is not resolved using by changing the IOS_SDK_VERSION to a newer version in the build-rockdb-ios.sh script.
I was hence looking for someone who has compiled a recent version of rocksdb/a wrapper of rocksdb for iOS and am looking for guidance.
TIA

Answer 1

Try RocksDB 6.x version, from 7.0 RocksDB need C++17。
Dropping some compiler support in 7.0#9388

Answer 2

#Xcode Version 13.2.1 (13C100)
$ brew install git
$ brew install cmake
$ git clone https://github.com/facebook/rocksdb.git
$ git checkout v6.29.5
$ export PORTABLE=1
$ export TARGET_OS=IOS
$ export ROCKSDB_LITE=1
$ export IOS_CROSS_COMPILE=1
#disable int128
$ export TEST_UINT128_COMPAT=1
$ export DISABLE_WARNING_AS_ERROR=1
$ export DEBUG_LEVEL=0
$ export EXTRA_CXXFLAGS="-DNPERF_CONTEXT -DNIOSTATS_CONTEXT"
$ make V=1 VERBOSE=1 -j16 static_lib