Add SPM support: vendored leveldb 1.22.5, wrapper kept verbatim MRC via -fno-objc-arc

[damian-kolasinski]

Adds Swift Package Manager support so consumers (KingsChat iOS) can drop both the Objective-LevelDB and leveldb-library CocoaPods — while keeping the wrapper sources verbatim MRC, byte-identical to master apart from exactly one bug fix.

What's inside

Package.swift

• swift-tools-version 5.9, platform iOS 15, cxxLanguageStandard: .gnucxx14.
• Product Objective-LevelDB built from target Objective_LevelDB. The target/module name deliberately matches the module name CocoaPods generated for this pod, so existing imports keep working unchanged:
  • #import <Objective_LevelDB/LevelDB.h>
  • #import <Objective_LevelDB/Objective-LevelDB-umbrella.h> (a matching umbrella header is shipped in the public headers)
• The wrapper stays MRC: ARC is disabled via cSettings: [.unsafeFlags(["-fno-objc-arc"])] — the same pattern as appunite/protobuf, proven to work through Tuist with revision pinning. Because of the unsafe flag, this package can only be consumed by revision/branch, not by semver version.
• Internal target LevelDBLibrary: the vendored leveldb C++ library. It is intentionally NOT named leveldb to avoid an SPM target-name collision with firebase/leveldb when both packages end up in the same dependency graph (e.g. alongside firebase-ios-sdk).

Vendored leveldb (vendor/leveldb)

• Sources copied from https://github.com/firebase/leveldb tag CocoaPods-1.22.5 (commit a0bc79961d7be727d258d33d5a6b2f1023270ba1) — the exact tree the leveldb-library CocoaPods pod (resolved as 1.22.5 by consumers today) is built from; upstream leveldb 1.22 plus Firebase's build patches.
• Excluded: all tests/benchmarks, db/leveldbutil.cc, Windows-specific files (env_windows*, windows_logger.h), db/c_test.c.
• Same build settings as the pod: LEVELDB_PLATFORM_POSIX, LEVELDB_IS_BIG_ENDIAN=0, HAVE_FULLFSYNC=1, links libc++, ships the pod's PrivacyInfo.xcprivacy.

The single wrapper change (vs master)

Classes/LevelDB.mm, initWithPath:name:andOptions:: _name = name; and _path = path; stored the ivars without retaining them (direct ivar assignment bypasses the retain property setters), leaving _name/_path dangling once the caller's strings are released. Fixed MRC-style; the complete wrapper diff vs master:

--- a/Classes/LevelDB.mm
+++ b/Classes/LevelDB.mm
@@ -117,8 +117,8 @@
 - (id) initWithPath:(NSString *)path name:(NSString *)name andOptions:(LevelDBOptions)opts {
     self = [super init];
     if (self) {
-        _name = name;
-        _path = path;
+        _name = [name retain];
+        _path = [path retain];
         
         leveldb::Options options;
@@ -664,6 +664,8 @@
 - (void) dealloc {
     [self close];
+    [_name release];
+    [_path release];
     [super dealloc];
 }

(master's dealloc never released either ivar, so the releases are added alongside.)

Everything else — all other wrapper sources, headers, and the podspec (requires_arc = false, version 2.1.4) — is byte-identical to master; git diff master -- Classes Objective-LevelDB.podspec shows only the two hunks above plus the new Classes/include/ shim headers.

Validation

• xcodebuild -scheme Objective-LevelDB -destination "generic/platform=iOS Simulator" build — succeeds (also generic/platform=iOS).
• A scratch ObjC consumer package depending on this package builds clean (fresh DerivedData, simulator + device) using the exact import spellings above and exercises databaseInLibraryWithName:, encoder/decoder blocks, setObject:forKey:, key/object prefix enumeration and NSStringFromLevelDBKey.
• Verified -fno-objc-arc lands after Xcode's default -fobjc-arc on the wrapper compile commands (last flag wins); MRC constructs like [super dealloc] would be hard compile errors under ARC, so the successful build is itself proof ARC is off.

https://claude.ai/code/session_01LTj6vGgu7NmTs7bjupWAGh