MB-54131: Corner cases when buffer not setup & formatting (#15)

* MB-54131: Corner cases when buffer not setup & formatting

* No need to export sizeOfFloat64, sizeOfVertex

Author: abhinavdangeti

s2/buffer_pool.go

@@ -46,19 +46,24 @@ func NewGeoBufferPool(maxSize int, minSize int) *GeoBufferPool {
 }
 
 func (b *GeoBufferPool) Get(size int) ([]byte) {
+	if b == nil {
+		// GeoBufferPool not setup
+		return make([]byte, size)
+	}
+
 	bufSize := b.minSize
 
 	for i := range b.buffers {
-		if size <= bufSize || i == len(b.buffers) - 1{
+		if size <= bufSize || i == len(b.buffers) - 1 {
 			if b.buffers[i] == nil {
 				b.buffers[i] = make([]byte, bufSize)
 			}
 
 			return b.buffers[i]
-		} else {
-			bufSize = bufSize * 2
 		}
+
+		bufSize = bufSize * 2
 	}
 
 	return nil
-}
+}

s2/encode.go

@@ -231,8 +231,8 @@ func (d *decoder) readFloat64Array(size int, buf []byte) int {
 	if size >= len(buf) {
 		_, d.err = io.ReadFull(d.r, buf)
 		return len(buf)
-	} else {
-		_, d.err = io.ReadFull(d.r, buf[0:size])
-		return size
 	}
+
+	_, d.err = io.ReadFull(d.r, buf[0:size])
+	return size
 }

s2/loop.go

@@ -19,15 +19,13 @@ import (
 	"fmt"
 	"io"
 	"math"
+	"reflect"
 
 	"github.com/golang/geo/r1"
 	"github.com/golang/geo/r3"
 	"github.com/golang/geo/s1"
 )
 
-const SizeOfFloat = 8
-const SizeOfVertex = 3 * SizeOfFloat
-
 // Loop represents a simple spherical polygon. It consists of a sequence
 // of vertices where the first vertex is implicitly connected to the
 // last. All loops are defined to have a CCW orientation, i.e. the interior of
@@ -1265,6 +1263,15 @@ func (l Loop) encode(e *encoder) {
 	l.bound.encode(e)
 }
 
+func init() {
+	var f64 float64
+	sizeOfFloat64 = int(reflect.TypeOf(f64).Size())
+	sizeOfVertex = 3 * sizeOfFloat64
+}
+
+var sizeOfFloat64 int
+var sizeOfVertex int
+
 // Decode decodes a loop.
 func (l *Loop) Decode(r io.Reader) error {
 	*l = Loop{}
@@ -1296,7 +1303,7 @@ func (l *Loop) decode(d *decoder) {
 	l.vertices = make([]Point, nvertices)
 
 	// Each vertex requires 24 bytes of storage
-	numBytesNeeded := int(nvertices) * SizeOfVertex
+	numBytesNeeded := int(nvertices) * sizeOfVertex
 
 	i := 0
 
@@ -1308,18 +1315,21 @@ func (l *Loop) decode(d *decoder) {
 			break
 		}
 
-		numBytesNeeded = numBytesNeeded - numBytesRead 
+		numBytesNeeded -= numBytesRead
 
 		// Parsing one vertex at a time into the vertex array of the loop
-		// by going through the buffer in steps of SizeOfVertex and converting
+		// by going through the buffer in steps of sizeOfVertex and converting
 		// floatSize worth of bytes into the float values
-		for j := 0; j < int(numBytesRead/SizeOfVertex); j++ {
-			l.vertices[i+j].X = math.Float64frombits(binary.LittleEndian.Uint64(arr[SizeOfFloat*(j*3) : SizeOfFloat*(j*3+1)]))
-			l.vertices[i+j].Y = math.Float64frombits(binary.LittleEndian.Uint64(arr[SizeOfFloat*(j*3+1) : SizeOfFloat*(j*3+2)]))
-			l.vertices[i+j].Z = math.Float64frombits(binary.LittleEndian.Uint64(arr[SizeOfFloat*(j*3+2) : SizeOfFloat*(j*3+3)]))
+		for j := 0; j < int(numBytesRead/sizeOfVertex); j++ {
+			l.vertices[i+j].X = math.Float64frombits(
+				binary.LittleEndian.Uint64(arr[sizeOfFloat64*(j*3) : sizeOfFloat64*(j*3+1)]))
+			l.vertices[i+j].Y = math.Float64frombits(
+				binary.LittleEndian.Uint64(arr[sizeOfFloat64*(j*3+1) : sizeOfFloat64*(j*3+2)]))
+			l.vertices[i+j].Z = math.Float64frombits(
+				binary.LittleEndian.Uint64(arr[sizeOfFloat64*(j*3+2) : sizeOfFloat64*(j*3+3)]))
 		}
 
-		i = i + int(numBytesRead/SizeOfVertex)
+		i += int(numBytesRead/sizeOfVertex)
 	}
 
 	l.index = NewShapeIndex()