From 29eeb5e3016e12da5bd3867e6ba582503f74404e Mon Sep 17 00:00:00 2001
From: "Sascha L. Teichmann" <sascha.teichmann@intevation.de>
Date: Fri, 24 Jul 2015 08:30:52 +0200
Subject: [PATCH] Implemented usage of coverage index in non-interleaved
 LevelDB backend. Untested, yet!

---
 cmd/mtredisalize/leveldb.go | 33 ++++++++++++++++++++-------------
 1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/cmd/mtredisalize/leveldb.go b/cmd/mtredisalize/leveldb.go
index f8ede70..b1307ca 100644
--- a/cmd/mtredisalize/leveldb.go
+++ b/cmd/mtredisalize/leveldb.go
@@ -274,14 +274,19 @@ func (ldbs *LevelDBSession) AllKeys(hash []byte, done chan struct{}) (keys chan
 	return
 }
 
-func (ldbs *LevelDBSession) SpatialQuery(hash, first, second []byte, done chan struct{}) (chan Block, error) {
+func (ldbs *LevelDBSession) SpatialQuery(
+	hash, first, second []byte,
+	done chan struct{}) (chan Block, error) {
+
 	if ldbs.backend.interleaved {
 		return ldbs.interleavedSpatialQuery(first, second, done)
 	}
 	return ldbs.plainSpatialQuery(first, second, done)
 }
 
-func (ldbs *LevelDBSession) plainSpatialQuery(first, second []byte, done chan struct{}) (blocks chan Block, err error) {
+func (ldbs *LevelDBSession) plainSpatialQuery(
+	first, second []byte,
+	done chan struct{}) (blocks chan Block, err error) {
 
 	var (
 		firstKey  int64
@@ -311,21 +316,20 @@ func (ldbs *LevelDBSession) plainSpatialQuery(first, second []byte, done chan st
 		it := ldbs.backend.db.NewIterator(ro)
 		defer it.Close()
 
-		a, b := common.Coord{X: c1.X}, common.Coord{X: c2.X}
-
+		var a, b common.Coord
 		var err error
 
-		for a.Z = c1.Z; a.Z <= c2.Z; a.Z++ {
-			b.Z = a.Z
-			for a.Y = c1.Y; a.Y <= c2.Y; a.Y++ {
+		for _, r := range ldbs.backend.coverage.Query(c1, c2) {
+			a.Z, b.Z = int16(r.Z), int16(r.Z)
+			a.X, b.X = int16(r.X1), int16(r.X2)
+			// log.Printf("y1 y2 x1 x2 z: %d %d, %d %d, %d\n", r.Y1, r.Y2, r.X1, r.X2, r.Z)
+			for a.Y = r.Y2; a.Y >= r.Y1; a.Y-- {
 				b.Y = a.Y
-				from, to := order(common.CoordToPlain(a), common.CoordToPlain(b))
+				from, to := common.CoordToPlain(a), common.CoordToPlain(b)
 				it.Seek(common.StringToBytes(from))
 				for ; it.Valid(); it.Next() {
-					var (
-						key = it.Key()
-						pos int64
-					)
+					key := it.Key()
+					var pos int64
 					if pos, err = common.DecodeStringFromBytes(key); err != nil {
 						log.Printf("decoding key failed: %s\n", err)
 						return
@@ -349,7 +353,10 @@ func (ldbs *LevelDBSession) plainSpatialQuery(first, second []byte, done chan st
 	return
 }
 
-func (ldbs *LevelDBSession) interleavedSpatialQuery(first, second []byte, done chan struct{}) (blocks chan Block, err error) {
+func (ldbs *LevelDBSession) interleavedSpatialQuery(
+	first, second []byte,
+	done chan struct{}) (blocks chan Block, err error) {
+
 	var (
 		firstKey  int64
 		secondKey int64