From 160ba8efa0c6c3689b50e0b4c3c9d05ca0077c62 Mon Sep 17 00:00:00 2001
From: Matthias Radestock <matthias.radestock@gmail.com>
Date: Mon, 31 Jul 2017 09:31:46 +0100
Subject: [PATCH 1/2] rename 'report_persistence' capability to
 'historic_reports'

since that better captures the intent - the UI doesn't care about
reports get stored, but what reports it can retrieve.
---
 common/xfer/constants.go | 6 +++---
 prog/app.go              | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/common/xfer/constants.go b/common/xfer/constants.go
index 04f151699..7b3c0469e 100644
--- a/common/xfer/constants.go
+++ b/common/xfer/constants.go
@@ -14,9 +14,9 @@ const (
 	ScopeProbeVersionHeader = "X-Scope-Probe-Version"
 )
 
-// ReportPersistenceCapability indicates whether probe reports end up in a
-// long-term storage and can be retrieved.
-const ReportPersistenceCapability = "report_persistence"
+// HistoricReportsCapability indicates whether reports older than the
+// current time (-app.window) can be retrieved.
+const HistoricReportsCapability = "historic_reports"
 
 // Details are some generic details that can be fetched from /api
 type Details struct {
diff --git a/prog/app.go b/prog/app.go
index 618c36a2c..ecd4df48e 100644
--- a/prog/app.go
+++ b/prog/app.go
@@ -295,7 +295,7 @@ func appMain(flags appFlags) {
 	}
 
 	capabilities := map[string]bool{
-		xfer.ReportPersistenceCapability: flags.s3URL != "local",
+		xfer.HistoricReportsCapability: flags.s3URL != "local",
 	}
 	handler := router(collector, controlRouter, pipeRouter, flags.externalUI, capabilities)
 	if flags.logHTTP {

From 1f95e3efd4f4912c643fbdb43e98c22377b73693 Mon Sep 17 00:00:00 2001
From: Matthias Radestock <matthias.radestock@gmail.com>
Date: Mon, 31 Jul 2017 09:58:31 +0100
Subject: [PATCH 2/2] obtain historic_reports capability from Reporter

---
 app/collector.go                 | 13 +++++++++++++
 app/multitenant/aws_collector.go |  4 ++++
 prog/app.go                      |  2 +-
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/app/collector.go b/app/collector.go
index 03319cdf0..d4b97dc6c 100644
--- a/app/collector.go
+++ b/app/collector.go
@@ -29,6 +29,7 @@ const reportQuantisationInterval = 3 * time.Second
 // interface for parts of the app, and several experimental components.
 type Reporter interface {
 	Report(context.Context, time.Time) (report.Report, error)
+	HasHistoricReports() bool
 	WaitOn(context.Context, chan struct{})
 	UnWait(context.Context, chan struct{})
 }
@@ -139,6 +140,12 @@ func (c *collector) Report(_ context.Context, timestamp time.Time) (report.Repor
 	return rpt, nil
 }
 
+// HasHistoricReports indicates whether the collector contains reports
+// older than now-app.window.
+func (c *collector) HasHistoricReports() bool {
+	return false
+}
+
 // remove reports older than the app.window
 func (c *collector) clean() {
 	var (
@@ -195,6 +202,12 @@ func (c StaticCollector) Report(context.Context, time.Time) (report.Report, erro
 	return report.Report(c), nil
 }
 
+// HasHistoricReports indicates whether the collector contains reports
+// older than now-app.window.
+func (c StaticCollector) HasHistoricReports() bool {
+	return false
+}
+
 // Add adds a report to the collector's internal state. It implements Adder.
 func (c StaticCollector) Add(context.Context, report.Report, []byte) error { return nil }
 
diff --git a/app/multitenant/aws_collector.go b/app/multitenant/aws_collector.go
index 9bba88633..964b5b241 100644
--- a/app/multitenant/aws_collector.go
+++ b/app/multitenant/aws_collector.go
@@ -340,6 +340,10 @@ func (c *awsCollector) Report(ctx context.Context, timestamp time.Time) (report.
 	return c.merger.Merge(reports).Upgrade(), nil
 }
 
+func (c *awsCollector) HasHistoricReports() bool {
+	return true
+}
+
 // calculateDynamoKeys generates the row & column keys for Dynamo.
 func calculateDynamoKeys(userid string, now time.Time) (string, string) {
 	rowKey := fmt.Sprintf("%s-%s", userid, strconv.FormatInt(now.UnixNano()/time.Hour.Nanoseconds(), 10))
diff --git a/prog/app.go b/prog/app.go
index ecd4df48e..5b06948d4 100644
--- a/prog/app.go
+++ b/prog/app.go
@@ -295,7 +295,7 @@ func appMain(flags appFlags) {
 	}
 
 	capabilities := map[string]bool{
-		xfer.HistoricReportsCapability: flags.s3URL != "local",
+		xfer.HistoricReportsCapability: collector.HasHistoricReports(),
 	}
 	handler := router(collector, controlRouter, pipeRouter, flags.externalUI, capabilities)
 	if flags.logHTTP {