From eea0b0bdca44fc9242eca21a1f6db5d2c20f0242 Mon Sep 17 00:00:00 2001
From: Rob Mulholand <rmulholand@8thlight.com>
Date: Mon, 23 Sep 2019 15:45:10 -0500
Subject: [PATCH] Return missing headers after starting block number

- Previously, we required that the first missing header match the
  configured starting block number. This helps guarantee that we have
  the necessary data for method polling in memory, but prevents the
  process from moving forward if restarted after the starting block
  has already been checked.
---
 .../header/repository/header_repository.go    | 23 +----------
 .../repository/header_repository_test.go      | 38 +++++++++++++++----
 2 files changed, 33 insertions(+), 28 deletions(-)

diff --git a/pkg/contract_watcher/header/repository/header_repository.go b/pkg/contract_watcher/header/repository/header_repository.go
index 91b8cd8c..78d96158 100644
--- a/pkg/contract_watcher/header/repository/header_repository.go
+++ b/pkg/contract_watcher/header/repository/header_repository.go
@@ -179,7 +179,7 @@ func (r *headerRepository) MissingHeaders(startingBlockNumber, endingBlockNumber
 				ORDER BY headers.block_number`
 		err = r.db.Select(&result, query, startingBlockNumber, endingBlockNumber, r.db.Node.ID)
 	}
-	return contiguousHeaders(result, startingBlockNumber), err
+	return continuousHeaders(result), err
 }
 
 // Returns missing headers for all of the provided checked_headers column ids
@@ -207,26 +207,7 @@ func (r *headerRepository) MissingHeadersForAll(startingBlockNumber, endingBlock
 		query = baseQuery + endStr
 		err = r.db.Select(&result, query, startingBlockNumber, endingBlockNumber, r.db.Node.ID)
 	}
-	return contiguousHeaders(result, startingBlockNumber), err
-}
-
-// Returns a continuous set of headers that is contiguous with the provided startingBlockNumber
-func contiguousHeaders(headers []core.Header, startingBlockNumber int64) []core.Header {
-	if len(headers) < 1 {
-		return headers
-	}
-	previousHeader := headers[0].BlockNumber
-	if previousHeader != startingBlockNumber {
-		return []core.Header{}
-	}
-	for i := 1; i < len(headers); i++ {
-		previousHeader++
-		if headers[i].BlockNumber != previousHeader {
-			return headers[:i]
-		}
-	}
-
-	return headers
+	return continuousHeaders(result), err
 }
 
 // Returns headers that have been checked for all of the provided event ids but not for the provided method ids
diff --git a/pkg/contract_watcher/header/repository/header_repository_test.go b/pkg/contract_watcher/header/repository/header_repository_test.go
index b29a8a35..a9a90824 100644
--- a/pkg/contract_watcher/header/repository/header_repository_test.go
+++ b/pkg/contract_watcher/header/repository/header_repository_test.go
@@ -203,6 +203,18 @@ var _ = Describe("Repository", func() {
 			Expect(missingHeaders[1].BlockNumber).To(Equal(int64(6194633)))
 		})
 
+		It("returns headers after starting header if starting header not missing", func() {
+			addLaterHeaders(coreHeaderRepo)
+			err := contractHeaderRepo.AddCheckColumns(eventIDs)
+			Expect(err).NotTo(HaveOccurred())
+
+			missingHeaders, err := contractHeaderRepo.MissingHeadersForAll(6194632, -1, eventIDs)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(len(missingHeaders)).To(Equal(2))
+			Expect(missingHeaders[0].BlockNumber).To(Equal(mocks.MockHeader3.BlockNumber))
+			Expect(missingHeaders[1].BlockNumber).To(Equal(mocks.MockHeader4.BlockNumber))
+		})
+
 		It("Fails if one of the eventIDs does not yet exist in check_headers table", func() {
 			addHeaders(coreHeaderRepo)
 			err := contractHeaderRepo.AddCheckColumns(eventIDs)
@@ -329,19 +341,31 @@ var _ = Describe("Repository", func() {
 			Expect(err).ToNot(HaveOccurred())
 			Expect(len(intersectionHeaders)).To(Equal(1))
 			Expect(intersectionHeaders[0].Id).To(Equal(headerID2))
-
 		})
 	})
 })
 
 func addHeaders(coreHeaderRepo repositories.HeaderRepository) {
-	coreHeaderRepo.CreateOrUpdateHeader(mocks.MockHeader1)
-	coreHeaderRepo.CreateOrUpdateHeader(mocks.MockHeader2)
-	coreHeaderRepo.CreateOrUpdateHeader(mocks.MockHeader3)
+	_, err := coreHeaderRepo.CreateOrUpdateHeader(mocks.MockHeader1)
+	Expect(err).NotTo(HaveOccurred())
+	_, err = coreHeaderRepo.CreateOrUpdateHeader(mocks.MockHeader2)
+	Expect(err).NotTo(HaveOccurred())
+	_, err = coreHeaderRepo.CreateOrUpdateHeader(mocks.MockHeader3)
+	Expect(err).NotTo(HaveOccurred())
 }
 
 func addDiscontinuousHeaders(coreHeaderRepo repositories.HeaderRepository) {
-	coreHeaderRepo.CreateOrUpdateHeader(mocks.MockHeader1)
-	coreHeaderRepo.CreateOrUpdateHeader(mocks.MockHeader2)
-	coreHeaderRepo.CreateOrUpdateHeader(mocks.MockHeader4)
+	_, err := coreHeaderRepo.CreateOrUpdateHeader(mocks.MockHeader1)
+	Expect(err).NotTo(HaveOccurred())
+	_, err = coreHeaderRepo.CreateOrUpdateHeader(mocks.MockHeader2)
+	Expect(err).NotTo(HaveOccurred())
+	_, err = coreHeaderRepo.CreateOrUpdateHeader(mocks.MockHeader4)
+	Expect(err).NotTo(HaveOccurred())
+}
+
+func addLaterHeaders(coreHeaderRepo repositories.HeaderRepository) {
+	_, err := coreHeaderRepo.CreateOrUpdateHeader(mocks.MockHeader3)
+	Expect(err).NotTo(HaveOccurred())
+	_, err = coreHeaderRepo.CreateOrUpdateHeader(mocks.MockHeader4)
+	Expect(err).NotTo(HaveOccurred())
 }