seperated out the db utilities. Also adding link for "other" views.

dbutil/dbutil.go

@@ -0,0 +1,97 @@
+package dbutil
+
+import (
+	"github.com/vbatts/imgsrv/hash"
+	"github.com/vbatts/imgsrv/types"
+	"labix.org/v2/mgo"
+	"labix.org/v2/mgo/bson"
+)
+
+type Util struct {
+	Gfs *mgo.GridFS
+}
+
+func (u Util) GetFileByFilename(filename string) (this_file types.File, err error) {
+	err = u.Gfs.Find(bson.M{"filename": filename}).One(&this_file)
+	if err != nil {
+		return this_file, err
+	}
+	return this_file, nil
+}
+
+func (u Util) GetFileRandom() (this_file types.File, err error) {
+	r := hash.Rand64()
+	err = u.Gfs.Find(bson.M{"random": bson.M{"$gt": r}}).One(&this_file)
+	if err != nil {
+		return this_file, err
+	}
+	if len(this_file.Md5) == 0 {
+		err = u.Gfs.Find(bson.M{"random": bson.M{"$lt": r}}).One(&this_file)
+	}
+	if err != nil {
+		return this_file, err
+	}
+	return this_file, nil
+}
+
+/* Check whether this types.File filename is on Mongo */
+func (u Util) HasFileByFilename(filename string) (exists bool, err error) {
+	c, err := u.Gfs.Find(bson.M{"filename": filename}).Count()
+	if err != nil {
+		return false, err
+	}
+	exists = (c > 0)
+	return exists, nil
+}
+
+func (u Util) HasFileByMd5(md5 string) (exists bool, err error) {
+	c, err := u.Gfs.Find(bson.M{"md5": md5}).Count()
+	if err != nil {
+		return false, err
+	}
+	exists = (c > 0)
+	return exists, nil
+}
+
+func (u Util) HasFileByKeyword(keyword string) (exists bool, err error) {
+	c, err := u.Gfs.Find(bson.M{"metadata": bson.M{"keywords": keyword}}).Count()
+	if err != nil {
+		return false, err
+	}
+	exists = (c > 0)
+	return exists, nil
+}
+
+/*
+get a list of keywords and their frequency count
+*/
+func (u Util) GetKeywords() (kp []types.KeywordCount, 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 := u.Gfs.Find(nil).MapReduce(job, &kp); err != nil {
+		return kp, err
+	}
+	return kp, nil
+}