dbutil: abstract out mongo Handler

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

dbutil/mongo/handle.go

@@ -0,0 +1,228 @@
+package mongo
+
+import (
+	"strings"
+
+	"github.com/vbatts/imgsrv/dbutil"
+	"github.com/vbatts/imgsrv/types"
+	"labix.org/v2/mgo"
+	"labix.org/v2/mgo/bson"
+)
+
+func init() {
+	dbutil.Handles["mongo"] = &mongoHandle{}
+}
+
+const defaultDbName = "filesrv"
+
+type dbConfig struct {
+	Seed   string // mongo host seed to Dial into
+	User   string // mongo credentials, if needed
+	Pass   string // mongo credentials, if needed
+	DbName string // mongo database name, if needed
+}
+
+type mongoHandle struct {
+	config  dbConfig
+	Session *mgo.Session
+	FileDb  *mgo.Database
+	Gfs     *mgo.GridFS
+}
+
+func (h *mongoHandle) Init(config interface{}) (err error) {
+	h.config = config.(dbConfig)
+
+	h.Session, err = mgo.Dial(h.config.Seed)
+	if err != nil {
+		return err
+	}
+
+	if len(h.config.DbName) > 0 {
+		h.FileDb = h.Session.DB(h.config.DbName)
+	} else {
+		h.FileDb = h.Session.DB(defaultDbName)
+	}
+
+	if len(h.config.User) > 0 && len(h.config.Pass) > 0 {
+		err = h.FileDb.Login(h.config.User, h.config.Pass)
+		if err != nil {
+			return err
+		}
+	}
+	h.Gfs = h.FileDb.GridFS("fs")
+	return nil
+}
+
+func (h mongoHandle) Close() error {
+	h.Session.Close()
+	return nil
+}
+
+// pass through for GridFs
+func (h mongoHandle) Open(filename string) (file *mgo.GridFile, err error) {
+	return h.Gfs.Open(strings.ToLower(filename))
+}
+
+// pass through for GridFs
+func (h mongoHandle) Create(filename string) (file *mgo.GridFile, err error) {
+	return h.Gfs.Create(strings.ToLower(filename))
+}
+
+// pass through for GridFs
+func (h mongoHandle) Remove(filename string) (err error) {
+	return h.Gfs.Remove(strings.ToLower(filename))
+}
+
+// Find files by their MD5 checksum
+func (h mongoHandle) FindFilesByMd5(md5 string) (files []types.File, err error) {
+	err = h.Gfs.Find(bson.M{"md5": md5}).Sort("-metadata.timestamp").All(&files)
+	return files, err
+}
+
+// match for file name
+// XXX this is not used
+func (h mongoHandle) FindFilesByName(filename string) (files []types.File, err error) {
+	err = h.Gfs.Find(bson.M{"filename": filename}).Sort("-metadata.timestamp").All(&files)
+	return files, err
+}
+
+// Case-insensitive pattern match for file name
+func (h mongoHandle) FindFilesByPatt(filenamePat string) (files []types.File, err error) {
+	err = h.Gfs.Find(bson.M{"filename": bson.M{"$regex": filenamePat, "$options": "i"}}).Sort("-metadata.timestamp").All(&files)
+	return files, err
+}
+
+// Case-insensitive pattern match for file name
+func (h mongoHandle) FindFilesByKeyword(keyword string) (files []types.File, err error) {
+	err = h.Gfs.Find(bson.M{"metadata.keywords": strings.ToLower(keyword)}).Sort("-metadata.timestamp").All(&files)
+	return files, err
+}
+
+// Get all the files.
+// Pass -1 for all files.
+func (h mongoHandle) GetFiles(limit int) (files []types.File, err error) {
+	//files = []types.File{}
+	if limit == -1 {
+		err = h.Gfs.Find(nil).Sort("-metadata.timestamp").All(&files)
+	} else {
+		err = h.Gfs.Find(nil).Sort("-metadata.timestamp").Limit(limit).All(&files)
+	}
+	return files, err
+}
+
+// Count the filename matches
+func (h mongoHandle) CountFiles(filename string) (count int, err error) {
+	query := h.Gfs.Find(bson.M{"filename": strings.ToLower(filename)})
+	return query.Count()
+}
+
+// Get one file back, by searching by file name
+func (h mongoHandle) GetFileByFilename(filename string) (thisFile types.File, err error) {
+	err = h.Gfs.Find(bson.M{"filename": strings.ToLower(filename)}).One(&thisFile)
+	if err != nil {
+		return thisFile, err
+	}
+	return thisFile, nil
+}
+
+// Check whether this types.File filename is on Mongo
+func (h mongoHandle) HasFileByFilename(filename string) (exists bool, err error) {
+	c, err := h.CountFiles(filename)
+	if err != nil {
+		return false, err
+	}
+	exists = (c > 0)
+	return exists, nil
+}
+
+// XXX this is not used
+func (h mongoHandle) HasFileByMd5(md5 string) (exists bool, err error) {
+	c, err := h.Gfs.Find(bson.M{"md5": md5}).Count()
+	if err != nil {
+		return false, err
+	}
+	exists = (c > 0)
+	return exists, nil
+}
+
+// XXX this is not used
+func (h mongoHandle) HasFileByKeyword(keyword string) (exists bool, err error) {
+	c, err := h.Gfs.Find(bson.M{"metadata": bson.M{"keywords": strings.ToLower(keyword)}}).Count()
+	if err != nil {
+		return false, err
+	}
+	exists = (c > 0)
+	return exists, nil
+}
+
+// get a list of file extensions and their frequency count
+func (h mongoHandle) GetExtensions() (kp []types.IdCount, err error) {
+	job := &mgo.MapReduce{
+		Map: `
+    function() {
+        if (!this.filename) {
+          return;
+        }
+
+        s = this.filename.split(".")
+        ext = s[s.length - 1] // get the last segment of the split
+        emit(ext,1);
+    }
+    `,
+		Reduce: `
+    function(previous, current) {
+      var count = 0;
+
+      for (index in current) {
+        count += current[index];
+      }
+
+      return count;
+    }
+    `,
+	}
+	if _, err := h.Gfs.Find(nil).MapReduce(job, &kp); err != nil {
+		return kp, err
+	}
+	// Less than effecient, but cleanest place to put this
+	for i := range kp {
+		kp[i].Root = "ext" // for extension. Maps to /ext/
+	}
+	return kp, nil
+}
+
+// get a list of keywords and their frequency count
+func (h mongoHandle) GetKeywords() (kp []types.IdCount, err error) {
+	job := &mgo.MapReduce{
+		Map: `
+    function() {
+        if (!this.metadata.keywords) {
+          return;
+        }
+
+        for (index in this.metadata.keywords) {
+          emit(this.metadata.keywords[index], 1);
+        }
+    }
+    `,
+		Reduce: `
+    function(previous, current) {
+      var count = 0;
+
+      for (index in current) {
+        count += current[index];
+      }
+
+      return count;
+    }
+    `,
+	}
+	if _, err := h.Gfs.Find(nil).MapReduce(job, &kp); err != nil {
+		return kp, err
+	}
+	// Less than effecient, but cleanest place to put this
+	for i := range kp {
+		kp[i].Root = "k" // for keyword. Maps to /k/
+	}
+	return kp, nil
+}