From 2dc9fc1626507bb54417fc4a1920b847cafb27a2 Mon Sep 17 00:00:00 2001
From: tobi <31960611+tsmethurst@users.noreply.github.com>
Date: Wed, 25 Aug 2021 15:34:33 +0200
Subject: Pg to bun (#148)

* start moving to bun

* changing more stuff

* more

* and yet more

* tests passing

* seems stable now

* more big changes

* small fix

* little fixes
---
 .../pgconn/internal/ctxwatch/context_watcher.go    | 64 ++++++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 vendor/github.com/jackc/pgconn/internal/ctxwatch/context_watcher.go

(limited to 'vendor/github.com/jackc/pgconn/internal')

diff --git a/vendor/github.com/jackc/pgconn/internal/ctxwatch/context_watcher.go b/vendor/github.com/jackc/pgconn/internal/ctxwatch/context_watcher.go
new file mode 100644
index 000000000..391f0b791
--- /dev/null
+++ b/vendor/github.com/jackc/pgconn/internal/ctxwatch/context_watcher.go
@@ -0,0 +1,64 @@
+package ctxwatch
+
+import (
+	"context"
+)
+
+// ContextWatcher watches a context and performs an action when the context is canceled. It can watch one context at a
+// time.
+type ContextWatcher struct {
+	onCancel             func()
+	onUnwatchAfterCancel func()
+	unwatchChan          chan struct{}
+	watchInProgress      bool
+	onCancelWasCalled    bool
+}
+
+// NewContextWatcher returns a ContextWatcher. onCancel will be called when a watched context is canceled.
+// OnUnwatchAfterCancel will be called when Unwatch is called and the watched context had already been canceled and
+// onCancel called.
+func NewContextWatcher(onCancel func(), onUnwatchAfterCancel func()) *ContextWatcher {
+	cw := &ContextWatcher{
+		onCancel:             onCancel,
+		onUnwatchAfterCancel: onUnwatchAfterCancel,
+		unwatchChan:          make(chan struct{}),
+	}
+
+	return cw
+}
+
+// Watch starts watching ctx. If ctx is canceled then the onCancel function passed to NewContextWatcher will be called.
+func (cw *ContextWatcher) Watch(ctx context.Context) {
+	if cw.watchInProgress {
+		panic("Watch already in progress")
+	}
+
+	cw.onCancelWasCalled = false
+
+	if ctx.Done() != nil {
+		cw.watchInProgress = true
+		go func() {
+			select {
+			case <-ctx.Done():
+				cw.onCancel()
+				cw.onCancelWasCalled = true
+				<-cw.unwatchChan
+			case <-cw.unwatchChan:
+			}
+		}()
+	} else {
+		cw.watchInProgress = false
+	}
+}
+
+// Unwatch stops watching the previously watched context. If the onCancel function passed to NewContextWatcher was
+// called then onUnwatchAfterCancel will also be called.
+func (cw *ContextWatcher) Unwatch() {
+	if cw.watchInProgress {
+		cw.unwatchChan <- struct{}{}
+		if cw.onCancelWasCalled {
+			cw.onUnwatchAfterCancel()
+		}
+		cw.watchInProgress = false
+	}
+}
-- 
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