review fixes

libraries/shared/storage/utils/bins.go

@@ -0,0 +1,45 @@
+// VulcanizeDB
+// Copyright © 2019 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package utils
+
+import "errors"
+
+func GetBlockHeightBins(startingBlock, endingBlock, batchSize uint64) ([][]uint64, error) {
+	if endingBlock < startingBlock {
+		return nil, errors.New("backfill: ending block number needs to be greater than starting block number")
+	}
+	if batchSize == 0 {
+		return nil, errors.New("backfill: batchsize needs to be greater than zero")
+	}
+	length := endingBlock - startingBlock + 1
+	numberOfBins := length / batchSize
+	remainder := length % batchSize
+	if remainder != 0 {
+		numberOfBins++
+	}
+	blockRangeBins := make([][]uint64, numberOfBins)
+	for i := range blockRangeBins {
+		nextBinStart := startingBlock + batchSize
+		blockRange := make([]uint64, 0, nextBinStart-startingBlock+1)
+		for j := startingBlock; j < nextBinStart && j <= endingBlock; j++ {
+			blockRange = append(blockRange, j)
+		}
+		startingBlock = nextBinStart
+		blockRangeBins[i] = blockRange
+	}
+	return blockRangeBins, nil
+}

libraries/shared/storage/utils/bins_test.go

@@ -0,0 +1,66 @@
+// VulcanizeDB
+// Copyright © 2019 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package utils_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"github.com/vulcanize/vulcanizedb/libraries/shared/storage/utils"
+)
+
+var _ = Describe("GetBlockHeightBins", func() {
+	It("splits a block range up into bins", func() {
+		var startingBlock uint64 = 1
+		var endingBlock uint64 = 10101
+		var batchSize uint64 = 100
+		blockRangeBins, err := utils.GetBlockHeightBins(startingBlock, endingBlock, batchSize)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(len(blockRangeBins)).To(Equal(102))
+		Expect(blockRangeBins[101]).To(Equal([]uint64{10101}))
+
+		startingBlock = 101
+		endingBlock = 10100
+		batchSize = 100
+		lastBin := make([]uint64, 0)
+		for i := 10001; i <= 10100; i++ {
+			lastBin = append(lastBin, uint64(i))
+		}
+		blockRangeBins, err = utils.GetBlockHeightBins(startingBlock, endingBlock, batchSize)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(len(blockRangeBins)).To(Equal(100))
+		Expect(blockRangeBins[99]).To(Equal(lastBin))
+	})
+
+	It("throws an error if the starting block is higher than the ending block", func() {
+		var startingBlock uint64 = 10102
+		var endingBlock uint64 = 10101
+		var batchSize uint64 = 100
+		_, err := utils.GetBlockHeightBins(startingBlock, endingBlock, batchSize)
+		Expect(err).To(HaveOccurred())
+		Expect(err.Error()).To(ContainSubstring("ending block number needs to be greater than starting block number"))
+	})
+
+	It("throws an error if the batch size is zero", func() {
+		var startingBlock uint64 = 1
+		var endingBlock uint64 = 10101
+		var batchSize uint64 = 0
+		_, err := utils.GetBlockHeightBins(startingBlock, endingBlock, batchSize)
+		Expect(err).To(HaveOccurred())
+		Expect(err.Error()).To(ContainSubstring("batchsize needs to be greater than zero"))
+	})
+})