From: mishaz <misha@curoverse.com>
Date: Thu, 8 Jan 2015 01:47:51 +0000 (+0000)
Subject: Added logger to write log messages that grow over time. Not working yet.
X-Git-Tag: 1.1.0~1505^2~65
X-Git-Url: https://git.arvados.org/arvados.git/commitdiff_plain/3594ad790c998c1b1711ea65057fcae9477986d4

Added logger to write log messages that grow over time. Not working yet.
---

diff --git a/sdk/go/logger/logger.go b/sdk/go/logger/logger.go
new file mode 100644
index 0000000000..6835750812
--- /dev/null
+++ b/sdk/go/logger/logger.go
@@ -0,0 +1,79 @@
+// Periodically writes a log to the Arvados SDK.
+//
+// This package is useful for maintaining a log object that is built
+// up over time. Every time the object is modified, it will be written
+// to the log. Writes will be throttled to no more than one every
+// WriteFrequencySeconds
+//
+// This package is safe for concurrent use.
+//
+// Usage:
+// arvLogger := logger.NewLogger(params)
+// logData := arvLogger.Acquire()  // This will block if others are using the logger
+// // Modify the logObject however you want here ..
+// logData = arvLogger.Release()  // This triggers the actual write, and replaces logObject with a nil pointer so you don't try to modify it when you're no longer holding the lock
+
+package logger
+
+import (
+	"git.curoverse.com/arvados.git/sdk/go/arvadosclient"
+	"log"
+	"sync"
+	"time"
+)
+
+const (
+	eventTypeLabel string = "event-type"
+	propertiesLabel string = "properties"
+)
+
+type LoggerParams struct {
+	Client arvadosclient.ArvadosClient  // The client we use to write log entries
+	EventType string  // The event type to assign to the log entry.
+	MinimumWriteInterval time.Duration  // Wait at least this long between log writes
+}
+
+type Logger struct {
+	data map[string]interface{}
+	lock sync.Locker
+	params LoggerParams
+}
+
+func NewLogger(params LoggerParams) *Logger {
+	l := &Logger{data: make(map[string]interface{}),
+		lock: &sync.Mutex{},
+		// TODO(misha): Consider copying the params so they're not
+		// modified after creation.
+		params: params}
+	l.data[propertiesLabel] = make(map[string]interface{})
+	return l
+}
+
+func (l *Logger) Acquire() map[string]interface{} {
+	l.lock.Lock()
+	return l.data[propertiesLabel].(map[string]interface{})
+}
+
+func (l *Logger) Release() map[string]interface{} {
+	// TODO(misha): Add a check (and storage) to make sure we respect MinimumWriteInterval
+	l.write()
+	l.lock.Unlock()
+	return nil
+}
+
+func (l *Logger) write() {
+	// Update the event type in case it was modified or is missing.
+	// l.data[eventTypeLabel] = l.params.EventType
+	// m := make(map[string]interface{})
+	// m["body"] = l.data
+	// //err := l.params.Client.Create("logs", l.data, nil)
+	// //err := l.params.Client.Create("logs", m, nil)
+	// var results map[string]interface{}
+	err := l.params.Client.Create("logs",
+		arvadosclient.Dict{"log": arvadosclient.Dict{
+			eventTypeLabel: l.params.EventType,
+			propertiesLabel: l.data}}, nil)
+	if err != nil {
+		log.Fatalf("Received error writing log: %v", err)
+	}
+}
diff --git a/sdk/go/logger/main/testlogger.go b/sdk/go/logger/main/testlogger.go
new file mode 100644
index 0000000000..5a12352043
--- /dev/null
+++ b/sdk/go/logger/main/testlogger.go
@@ -0,0 +1,32 @@
+// This binary tests the logger package.
+// It's not a standard unit test. Instead it writes to the actual log
+// and you have to clean up after it.
+
+package main
+
+import (
+	"git.curoverse.com/arvados.git/sdk/go/arvadosclient"
+	"git.curoverse.com/arvados.git/sdk/go/logger"
+	"log"
+)
+
+const (
+	eventType string = "experimental-logger-testing"
+)
+
+
+func main() {
+	arv, err := arvadosclient.MakeArvadosClient()
+	if err != nil {
+		log.Fatalf("Error setting up arvados client %v", err)
+	}
+
+	l := logger.NewLogger(logger.LoggerParams{Client: arv,
+		EventType: eventType,
+		// No minimum write interval
+	})
+
+	logData := l.Acquire()
+	logData["Ninja"] = "Misha"
+	logData = l.Release()
+}