rocksdb: add WaitForCompact() (#54)

Summary:
Pull Request resolved: #54

RocksDB 8.7 was released with C bindings for `WaitForCompact()` call that was added on our request. Update CGO wrapper with those bindings.

Reviewed By: leoleovich

Differential Revision: D51029439

fbshipit-source-id: 7ad58bf8992a8a22b9872fb6f7bee1a1b2ad6b60

.github/workflows/lint.yml

@@ -3,15 +3,18 @@ on: [push, pull_request]
 jobs:
   lint:
     runs-on: ubuntu-22.04
+    env:
+      CGO_LDFLAGS_ALLOW: .*
+      CGO_CFLAGS_ALLOW: .*
     steps:
       - uses: actions/checkout@v2
         with:
           submodules: recursive
       - uses: actions/setup-go@v2
         with:
           go-version: 1.18
-      - name: "Install Rocks"
-        run: sudo bash .github/scripts/install_rocks_stable.sh
+      - name: "Install RocksDB"
+        run: sudo bash .github/scripts/install_rocks_head.sh
       - uses: golangci/golangci-lint-action@v3
         with:
           working-directory: dnsrocks

dnsrocks/cgo-rocksdb/db.go

@@ -341,6 +341,17 @@ func (db *RocksDB) CompactRangeAll() {
 	)
 }
 
+// WaitForCompact waits for all currently running compactions to finish, optionally closing the DB afterwards
+func (db *RocksDB) WaitForCompact(options *WaitForCompactOptions) error {
+	var cError *C.char
+	C.rocksdb_wait_for_compact(db.cDB, options.cOptions, &cError)
+	if cError != nil {
+		defer C.rocksdb_free(unsafe.Pointer(cError))
+		return errors.New(C.GoString(cError))
+	}
+	return nil
+}
+
 // GetProperty returns value of db property
 func (db *RocksDB) GetProperty(prop string) string {
 	cprop := C.CString(prop)

dnsrocks/cgo-rocksdb/options.go

@@ -27,7 +27,10 @@ const int BOOL_INT_TRUE = 1;
 import (
 	"C"
 )
-import "unsafe"
+import (
+	"time"
+	"unsafe"
+)
 
 // BoolToChar is a helper to convert boolean value to C.uchar
 func BoolToChar(b bool) C.uchar {
@@ -37,6 +40,11 @@ func BoolToChar(b bool) C.uchar {
 	return C.BOOL_CHAR_FALSE
 }
 
+// CharToBool converts C.uchar to boolean
+func CharToBool(cChar C.uchar) bool {
+	return cChar != C.BOOL_CHAR_FALSE
+}
+
 // DefaultCompactionMemtableMemoryBudget is the default for compaction
 // memory usage (src/include/rocksdb/options.h).
 const DefaultCompactionMemtableMemoryBudget uint64 = 512 * 1024 * 1024
@@ -474,3 +482,61 @@ func (readOptions *ReadOptions) SetIterateUpperBound(key []byte) {
 	cKeyPtr, cKeyLen := bytesToPtr(key)
 	C.rocksdb_readoptions_set_iterate_upper_bound(readOptions.cReadOptions, cKeyPtr, cKeyLen)
 }
+
+// WaitForCompactOptions is a set of options for WaitForCompact call
+type WaitForCompactOptions struct {
+	cOptions *C.rocksdb_wait_for_compact_options_t
+}
+
+// NewWaitForCompactOptions creates new WaitForCompactOptions
+func NewWaitForCompactOptions() *WaitForCompactOptions {
+	return &WaitForCompactOptions{
+		cOptions: C.rocksdb_wait_for_compact_options_create(),
+	}
+}
+
+// SetAbortOnPause sets option to abort waiting in case of a pause (PauseBackgroundWork() called, see
+// https://github.com/facebook/rocksdb/blob/2648e0a747303e63796315049b9005c7320356c0/include/rocksdb/options.h#L2165
+func (options *WaitForCompactOptions) SetAbortOnPause(v bool) {
+	C.rocksdb_wait_for_compact_options_set_abort_on_pause(options.cOptions, BoolToChar(v))
+}
+
+// GetAbortOnPause returns value of AbortOnPause option
+func (options *WaitForCompactOptions) GetAbortOnPause() bool {
+	return CharToBool(C.rocksdb_wait_for_compact_options_get_abort_on_pause(options.cOptions))
+}
+
+// SetFlush sets option to flush all column families before starting to wait, see
+// https://github.com/facebook/rocksdb/blob/2648e0a747303e63796315049b9005c7320356c0/include/rocksdb/options.h#L2165
+func (options *WaitForCompactOptions) SetFlush(v bool) {
+	C.rocksdb_wait_for_compact_options_set_flush(options.cOptions, BoolToChar(v))
+}
+
+// GetFlush returns value of Flush option
+func (options *WaitForCompactOptions) GetFlush() bool {
+	return CharToBool(C.rocksdb_wait_for_compact_options_get_flush(options.cOptions))
+}
+
+// SetCloseDB sets option to call Close() after waiting is done, see
+// https://github.com/facebook/rocksdb/blob/2648e0a747303e63796315049b9005c7320356c0/include/rocksdb/options.h#L2165
+func (options *WaitForCompactOptions) SetCloseDB(v bool) {
+	C.rocksdb_wait_for_compact_options_set_close_db(options.cOptions, BoolToChar(v))
+}
+
+// GetCloseDB returns value of CloseDB option
+func (options *WaitForCompactOptions) GetCloseDB() bool {
+	return CharToBool(C.rocksdb_wait_for_compact_options_get_close_db(options.cOptions))
+}
+
+// SetTimeout sets timeout for waiting for compaction to complete.
+// When timeout == 0, WaitForCompact() will wait as long as there's background work to finish.
+// See https://github.com/facebook/rocksdb/blob/2648e0a747303e63796315049b9005c7320356c0/include/rocksdb/options.h#L2165
+func (options *WaitForCompactOptions) SetTimeout(d time.Duration) {
+	C.rocksdb_wait_for_compact_options_set_timeout(options.cOptions, C.uint64_t(d.Microseconds()))
+}
+
+// GetTimeout returns value of Timeout option
+func (options *WaitForCompactOptions) GetTimeout() time.Duration {
+	t := C.rocksdb_wait_for_compact_options_get_timeout(options.cOptions)
+	return time.Duration(t) * time.Microsecond
+}

dnsrocks/docs/building.md

@@ -1,7 +1,7 @@
 # Building DNSRocks
 
 ## Prerequisites
-- [Rocksdb](https://github.com/facebook/rocksdb/releases) 7.3 or newer
+- [Rocksdb](https://github.com/facebook/rocksdb/releases) 8.7 or newer
 - [Go 1.18](https://github.com/facebook/dns/blob/main/dnsrocks/go.mod#L3)