From 0790470692ec1170e3ce5c58a88ff0aa029737dd Mon Sep 17 00:00:00 2001
From: Lars-Magnus Skog <ralphtheninja@riseup.net>
Date: Sat, 8 Dec 2018 23:35:23 +0100
Subject: [PATCH] Implement db_compact_range()

---
 binding.cc   | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 leveldown.js | 17 +++--------------
 2 files changed, 55 insertions(+), 14 deletions(-)

diff --git a/binding.cc b/binding.cc
index 788ac893..96d81dba 100644
--- a/binding.cc
+++ b/binding.cc
@@ -381,6 +381,11 @@ struct Database {
     return size;
   }
 
+  void CompactRange (const leveldb::Slice* start,
+                     const leveldb::Slice* end) {
+    db_->CompactRange(start, end);
+  }
+
   const leveldb::Snapshot* NewSnapshot () {
     return db_->GetSnapshot();
   }
@@ -1109,6 +1114,52 @@ NAPI_METHOD(db_approximate_size) {
   NAPI_RETURN_UNDEFINED();
 }
 
+/**
+ * Worker class for getting a value from a database.
+ */
+struct CompactRangeWorker : public BaseWorker {
+  CompactRangeWorker (napi_env env,
+                      Database* database,
+                      napi_value callback,
+                      leveldb::Slice start,
+                      leveldb::Slice end)
+    : BaseWorker(env, database, callback, "leveldown.db.compact_range"),
+      start_(start), end_(end) {}
+
+  virtual ~CompactRangeWorker () {
+    // TODO clean up start_ and end_ slices
+    // See DisposeStringOrBufferFromSlice()
+  }
+
+  virtual void DoExecute () {
+    database_->CompactRange(&start_, &end_);
+  }
+
+  leveldb::Slice start_;
+  leveldb::Slice end_;
+};
+
+/**
+ * Compacts a range.
+ */
+NAPI_METHOD(db_compact_range) {
+  NAPI_ARGV(4);
+  NAPI_DB_CONTEXT();
+
+  leveldb::Slice start = ToSlice(env, argv[1]);
+  leveldb::Slice end = ToSlice(env, argv[2]);
+  napi_value callback = argv[3];
+
+  CompactRangeWorker* worker  = new CompactRangeWorker(env,
+                                                       database,
+                                                       callback,
+                                                       start,
+                                                       end);
+  worker->Queue();
+
+  NAPI_RETURN_UNDEFINED();
+}
+
 /**
  * Runs when an Iterator is garbage collected.
  */
@@ -1777,6 +1828,7 @@ NAPI_INIT() {
   NAPI_EXPORT_FUNCTION(db_get);
   NAPI_EXPORT_FUNCTION(db_del);
   NAPI_EXPORT_FUNCTION(db_approximate_size);
+  NAPI_EXPORT_FUNCTION(db_compact_range);
 
   /**
    * Iterator related functions.
diff --git a/leveldown.js b/leveldown.js
index 1b09b8e9..a7c68c3e 100644
--- a/leveldown.js
+++ b/leveldown.js
@@ -22,12 +22,7 @@ function LevelDOWN (location) {
 util.inherits(LevelDOWN, AbstractLevelDOWN)
 
 LevelDOWN.prototype._open = function (options, callback) {
-  binding.db_open(
-    this.context,
-    this.location,
-    options,
-    callback
-  )
+  binding.db_open(this.context, this.location, options, callback)
 }
 
 LevelDOWN.prototype._close = function (callback) {
@@ -43,13 +38,7 @@ LevelDOWN.prototype._serializeValue = function (value) {
 }
 
 LevelDOWN.prototype._put = function (key, value, options, callback) {
-  binding.db_put(
-    this.context,
-    key,
-    value,
-    options,
-    callback
-  )
+  binding.db_put(this.context, key, value, options, callback)
 }
 
 LevelDOWN.prototype._get = function (key, options, callback) {
@@ -101,7 +90,7 @@ LevelDOWN.prototype.compactRange = function (start, end, callback) {
   start = this._serializeKey(start)
   end = this._serializeKey(end)
 
-  this.binding.compactRange(start, end, callback)
+  binding.db_compact_range(this.context, start, end, callback)
 }
 
 LevelDOWN.prototype.getProperty = function (property) {