iodine is part of minio now

pkg/iodine/iodine.go

@@ -0,0 +1,208 @@
+/*
+ * Iodine, (C) 2015 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package iodine
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path"
+	"reflect"
+	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/dustin/go-humanize"
+)
+
+// Error is the iodine error which contains a pointer to the original error
+// and stack traces.
+type Error struct {
+	EmbeddedError error `json:"-"`
+	ErrorMessage  string
+	ErrorType     string
+
+	Stack []StackEntry
+}
+
+// StackEntry contains the entry in the stack trace
+type StackEntry struct {
+	Host string
+	File string
+	Func string
+	Line int
+	Data map[string]string
+}
+
+var gopath string
+
+var globalState = struct {
+	sync.RWMutex
+	m map[string]string
+}{m: make(map[string]string)}
+
+// SetGlobalState - set global state
+func SetGlobalState(key, value string) {
+	globalState.Lock()
+	globalState.m[key] = value
+	globalState.Unlock()
+}
+
+// ClearGlobalState - clear info in globalState struct
+func ClearGlobalState() {
+	globalState.Lock()
+	for k := range globalState.m {
+		delete(globalState.m, k)
+	}
+	globalState.Unlock()
+}
+
+// GetGlobalState - get map from globalState struct
+func GetGlobalState() map[string]string {
+	result := make(map[string]string)
+	globalState.RLock()
+	for k, v := range globalState.m {
+		result[k] = v
+	}
+	globalState.RUnlock()
+	return result
+}
+
+// GetGlobalStateKey - get value for key from globalState struct
+func GetGlobalStateKey(k string) string {
+	result, ok := globalState.m[k]
+	if !ok {
+		return ""
+	}
+	return result
+}
+
+// New - instantiate an error, turning it into an iodine error.
+// Adds an initial stack trace.
+func New(err error, data map[string]string) error {
+	if err != nil {
+		entry := createStackEntry()
+		var newErr Error
+
+		// check if error is wrapped
+		switch typedError := err.(type) {
+		case Error:
+			{
+				newErr = typedError
+			}
+		default:
+			{
+				newErr = Error{
+					EmbeddedError: err,
+					ErrorMessage:  err.Error(),
+					ErrorType:     reflect.TypeOf(err).String(),
+					Stack:         []StackEntry{},
+				}
+			}
+		}
+		for k, v := range data {
+			entry.Data[k] = v
+		}
+		newErr.Stack = append(newErr.Stack, entry)
+		return newErr
+	}
+	return nil
+}
+
+// createStackEntry - create stack entries
+func createStackEntry() StackEntry {
+	host, _ := os.Hostname()
+	pc, file, line, _ := runtime.Caller(2)
+	function := runtime.FuncForPC(pc).Name()
+	_, function = path.Split(function)
+	file = strings.TrimPrefix(file, gopath) // trim gopath from file
+
+	data := GetGlobalState()
+	for k, v := range getSystemData() {
+		data[k] = v
+	}
+
+	entry := StackEntry{
+		Host: host,
+		File: file,
+		Func: function,
+		Line: line,
+		Data: data,
+	}
+	return entry
+}
+
+func getSystemData() map[string]string {
+	host, err := os.Hostname()
+	if err != nil {
+		host = ""
+	}
+	memstats := &runtime.MemStats{}
+	runtime.ReadMemStats(memstats)
+	return map[string]string{
+		"sys.host":               host,
+		"sys.os":                 runtime.GOOS,
+		"sys.arch":               runtime.GOARCH,
+		"sys.go":                 runtime.Version(),
+		"sys.cpus":               strconv.Itoa(runtime.NumCPU()),
+		"sys.mem.used":           humanize.Bytes(memstats.Alloc),
+		"sys.mem.allocated":      humanize.Bytes(memstats.TotalAlloc),
+		"sys.mem.heap.used":      humanize.Bytes(memstats.HeapAlloc),
+		"sys.mem.heap.allocated": humanize.Bytes(memstats.HeapSys),
+	}
+}
+
+// Annotate an error with a stack entry and returns itself
+//func (err *WrappedError) Annotate(info map[string]string) *WrappedError {
+//	entry := createStackEntry()
+//	for k, v := range info {
+//		entry.Data[k] = v
+//	}
+//	err.Stack = append(err.Stack, entry)
+//	return err
+//}
+
+// EmitJSON writes JSON output for the error
+func (err Error) EmitJSON() ([]byte, error) {
+	return json.Marshal(err)
+}
+
+// EmitHumanReadable returns a human readable error message
+func (err Error) EmitHumanReadable() string {
+	var errorBuffer bytes.Buffer
+	fmt.Fprintln(&errorBuffer, err.ErrorMessage)
+	for i, entry := range err.Stack {
+		prettyData, _ := json.Marshal(entry.Data)
+		fmt.Fprintln(&errorBuffer, "-", i, entry.Host+":"+entry.File+":"+strconv.Itoa(entry.Line)+" "+entry.Func+"():", string(prettyData))
+	}
+	return string(errorBuffer.Bytes())
+}
+
+// Emits the original error message
+func (err Error) Error() string {
+	return err.EmitHumanReadable()
+}
+
+func init() {
+	_, iodineFile, _, _ := runtime.Caller(0)
+	iodineFile = path.Dir(iodineFile)   // trim iodine.go
+	iodineFile = path.Dir(iodineFile)   // trim iodine
+	iodineFile = path.Dir(iodineFile)   // trim minio-io
+	gopath = path.Dir(iodineFile) + "/" // trim github.com
+}