Initial Commit

boltrest.go

@@ -0,0 +1,164 @@
+package boltrest
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/boltdb/bolt"
+)
+
+// This a custom library for saving/syncing data
+// in a local bolt db and a remote db through a
+// rest api.
+
+// Custom BoltRest DB keys:
+//	__BR_LastUpdate: <RFC3339 Timestamp>
+
+// DB is a struct for accomplishing this
+type DB struct {
+	localFile string
+	remoteURL string
+	apiToken  string
+	remoteMD5 string
+	online    bool
+	localDB   *bolt.DB
+}
+
+// Open returns the DB object
+func Open(filename string) (*DB, error) {
+	var err error
+	b := DB{localFile: filename}
+	b.localDB, err = bolt.Open(filename, 0644, nil)
+	if err != nil {
+		return nil, err
+	}
+	return &b, nil
+}
+
+// GetValue returns the value at path
+// path is a '/' separated list of tokens
+// the last token is a key, all others are buckets
+func (b *DB) GetValue(path []string, key string) (string, error) {
+	var err error
+	var ret string
+	// TODO: Make sure local db is fresh (or offline)
+
+	b.localDB.View(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket([]byte(path[0]))
+		if bkt == nil {
+			return fmt.Errorf("Couldn't find bucket " + path[0])
+		}
+		var newBkt *bolt.Bucket
+		for idx := 1; idx < len(path); idx++ {
+			newBkt = bkt.Bucket([]byte(path[idx]))
+			if newBkt == nil {
+				return fmt.Errorf("Couldn't find bucket " + strings.Join(path[:idx], "/"))
+			}
+		}
+		// newBkt should have the last bucket in the path
+		ret = string(newBkt.Get([]byte(key)))
+		return nil
+	})
+	return ret, err
+}
+
+// SetValue sets the value at path to val
+// path is a '/' separated list of tokens
+// the last token is a key, all others are buckets
+func (b *DB) SetValue(path []string, key, val string) error {
+	var err error
+	b.localDB.Update(func(tx *bolt.Tx) error {
+		newBkt := tx.Bucket([]byte(path[0]))
+		if newBkt == nil {
+			return fmt.Errorf("Couldn't find bucket " + path[0])
+		}
+		for idx := 1; idx < len(path); idx++ {
+			newBkt, err = newBkt.CreateBucketIfNotExists([]byte(path[idx]))
+			if err != nil {
+				return err
+			}
+		}
+		// newBkt should have the last bucket in the path
+		return newBkt.Put([]byte(key), []byte(val))
+	})
+	return err
+}
+
+// GetInt returns the value at 'path'
+// path is a '/' separated list of tokens
+// the last token is a key, all others are buckets
+// If the value cannot be parsed as an int, error
+func (b *DB) GetInt(path []string, key string) (int, error) {
+	var ret int
+	r, err := b.GetValue(path, key)
+	if err == nil {
+		ret, err = strconv.Atoi(r)
+	}
+	return ret, err
+}
+
+// SetInt Sets an integer value
+func (b *DB) SetInt(path []string, key string, val int) error {
+	return b.SetValue(path, key, strconv.Itoa(val))
+}
+
+// GetBool returns the value at 'path'
+// If the value cannot be parsed as a bool, error
+// We check 'true/false' and '1/0', else error
+func (b *DB) GetBool(path []string, key string) (bool, error) {
+	var ret bool
+	r, err := b.GetValue(path, key)
+	if err == nil {
+		if r == "true" || r == "1" {
+			ret = true
+		} else if r != "false" && r != "0" {
+			err = fmt.Errorf("Cannot parse as a boolean")
+		}
+	}
+	return ret, err
+}
+
+// SetBool Sets a boolean value
+func (b *DB) SetBool(path []string, key string, val bool) error {
+	if val {
+		return b.SetValue(path, key, "true")
+	}
+	return b.SetValue(path, key, "false")
+}
+
+// GetTimestamp returns the value at 'path'
+// If the value cannot be parsed as a RFC3339, error
+func (b *DB) GetTimestamp(path []string, key string) (time.Time, error) {
+	r, err := b.GetValue(path, key)
+	if err == nil {
+		return time.Parse(time.RFC3339, r)
+	}
+	return time.Unix(0, 0), err
+}
+
+// SetTimestamp returns the value at 'path'
+func (b *DB) SetTimestamp(path []string, key string, val time.Time) error {
+	return b.SetValue(path, key, val.Format(time.RFC3339))
+}
+
+type setURLResponse struct {
+	dbMD5 string
+}
+
+// SetURL sets the DB's remote URL
+func (b *DB) SetURL(url string) (bool, string) {
+	resp, err := http.Get(url)
+	if err != nil {
+		return false, ""
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	sur := setURLResponse{}
+	json.Unmarshal(body, sur)
+	return true, sur.dbMD5
+}