struct mapping cleanup

README.md

@@ -1,6 +1,7 @@
 # About
 
-Gossie is a Go library with a low level wrapper for the Cassandra 1.0 Thrift bindings with utilities for connection pooling, primitive type marshaling and easy query building. It also includes a higher level layer that allows mapping structs to Cassandra column famlilies, with support for advanced features like composite column names.
+Gossie is a Go library for Apache Cassandra. It includes a wrapper for the Cassandra 1.0 Thrift bindings with utilities for connection pooling, primitive type marshaling and easy query building. It also includes a higher level layer that allows mapping structs to Cassandra column famlilies, with support for advanced features like composite column names.
+
 
 # Requeriments
 
@@ -15,6 +16,7 @@ Installing thrift4go under GOPATH in Go 1:
 3) go install thrift
 ```
 
+
 # Installing
 
 There is no need to generate a Cassandra Thrift biding, I am providing one with Gossie (and the whole point is not to have to use it!)
@@ -40,6 +42,7 @@ GOPATH=$GOPATH:`pwd` go test gossie
 
 Launch a Cassandra instance in localhost:9160, create a keyspace named TestGossie, and execute the provided schema-test.txt to create the test column families. Now you can run the Gossie tests.
 
+
 # Quickstart
 
 ### Connection pooling
@@ -68,23 +71,23 @@ The low level interface is based on passing []byte values for everything, mirror
 
 ### Struct maping
 
-The first part of the high level Gossie interface is the Map/Unmap functions. These functions allow to convert Go structs into Row-s, and they have support of advanced features like composites or overriding column names and types.
+The first part of the high level Gossie interface is the Map/Unmap functions. These functions allow to convert Go structs into Rows, and they have support of advanced features like composites or overriding column names and types.
 
 ```Go
 /*
 In CQL 3.0:
-CREATE TABLE timeline (
-    user_id varchar,
-    tweet_id bigint,
-    author varchar,
-    body varchar,
-    PRIMARY KEY (user_id, tweet_id)
+CREATE TABLE Timeline (
+    UserID varchar,
+    TweetID bigint,
+    Author varchar,
+    Body varchar,
+    PRIMARY KEY (UserID, TweetID)
 );
 */
 
 // In Gossie:
 type Timeline struct {
-	UserID  string  `cf:"Timeline" key:"UserID" col:"TweetID,*name" val:"*value"`
+	UserID  string  `cf:"Timeline" key:"UserID,TweetID"`
 	TweetID int64
 	Author  string
 	Body    string
@@ -94,6 +97,10 @@ row, err = gossie.Map(&Timeline{"userid", 10000000000004, "Author Name", "Hey th
 err = pool.Mutation().Insert("Timeline", row).Run()
 ````
 
+The `cf` field tag names the column family of this struct, and the `key` field tag starts by naming the field that represents the row key, followed by zero or more fields that represent the components of a composite column name. Any other field not referenced in the `key` will be used as a column value, and its name used as a the column name, or appended to the end of the composite as the last component, if the struct had a composite. The `cf` and `key` field tags can appear at any field in the struct.
+
+The `name` field tag will change the column name to its value when the field it appears on is (un)marhsaled to/from a Cassandra row column. The `type` field tag allows to override the default type Go<->Cassandra type mapping used by Gossie for the field it appears on.
+
 ### Cursors
 
 As a convenient wrapper over Map/Unmap and the Query/Mutation interfaces Gossie provides the Cursor interface. This wrapper implements a classic database cursor over rows and composite row slices. Example:
@@ -117,7 +124,15 @@ err = cursor.Read(tweet2)
 // 10000000000004, or gossie.ErrorNotFound was returned in case it was not found
 ````
 
-Comming soon: range reads for composites with buffering and paging
+
+# Planned features
+
+- Cursor: range reads for composites with buffering and paging
+- Cursor: secondary index read with buffering and paging
+- Cursor: multiget reads with buffering and paging
+- Cursor: batching writes
+- High level mapping for Go slices
+- High level mapping for Go maps
 
 
 # License

src/gossie/cursor.go

@@ -2,7 +2,6 @@ package gossie
 
 import (
 	"errors"
-	"fmt"
 )
 
 /*
@@ -12,8 +11,6 @@ todo:
     buffering for slicing and range get
     Next/Prev for the buffering with autopaging
 
-    isSliceColumn == true
-
     Search() and interface(s) for indexed get
 
     multiget
@@ -57,12 +54,12 @@ func makeCursor(cp *connectionPool) (c *cursor) {
 
 func (c *cursor) Write(source interface{}) error {
 
-	row, ms, err := internalMap(source)
+	row, mi, err := internalMap(source)
 	if err != nil {
 		return err
 	}
 
-	if err = c.pool.Mutation().Insert(ms.sm.cf, row).Run(); err != nil {
+	if err = c.pool.Mutation().Insert(mi.m.cf, row).Run(); err != nil {
 		return err
 	}
 
@@ -72,61 +69,38 @@ func (c *cursor) Write(source interface{}) error {
 func (c *cursor) Read(source interface{}) error {
 
 	// deconstruct the source struct into a reflect.Value and a (cached) struct mapping
-	ms, err := newMappedStruct(source)
+	mi, err := newMappedInstance(source)
 	if err != nil {
 		return err
 	}
 
 	// sanity checks
-	if ms.sm.isSliceColumn {
-		return errors.New(fmt.Sprint("Slice field in col tag is unsuported in Cursor for now, check back soon!"))
-	}
-
 	// marshal the key field
-	key, err := ms.marshalKey()
+	key, err := mi.m.key.marshalValue(&mi.v)
 	if err != nil {
 		return err
 	}
 
 	// start building the query
-	q := c.pool.Query().Cf(ms.sm.cf)
+	q := c.pool.Query().Cf(mi.m.cf)
 
 	// build a slice composite comparator if needed
-	if ms.sm.isCompositeColumn {
+	if len(mi.m.composite) > 0 {
 		// iterate over the components and set an equality comparison for every simple field
 		start := make([]byte, 0)
 		end := make([]byte, 0)
-		var component int
-		for component = 0; component < len(ms.sm.columns); component++ {
-			fm := ms.sm.columns[component]
-			if fm.fieldKind != baseTypeField {
-				break
-			}
-			b, err := ms.mapColumn(baseTypeField, fm, 0)
+		for _, f := range mi.m.composite {
+			b, err := f.marshalValue(&mi.v)
 			if err != nil {
 				return err
 			}
-			start = packComposite(start, b, eocEquals)
-			end = packComposite(end, b, eocGreater)
+			start = append(start, packComposite(b, eocEquals)...)
+			end = append(end, packComposite(b, eocGreater)...)
 		}
-
-		/*if component < len(ms.sm.columns) {
-		    // we still got one to go, this means the last one was an iterable non-fixed type (*name or go slice)
-		    //fm := ms.sm.columns[component]
-		    // TODO: this will only work for *name
-		    b := make([]byte, 0)
-		    start = packComposite(start, b, o[6], o[7], o[8])
-		    end = packComposite(end, b, o[9], o[10], o[11])
-		}*/
-
 		// TODO: fix hardcoded number of columns
 		q.Slice(&Slice{Start: start, End: end, Count: 100})
 	}
 
-	//isCompositeColumn bool
-	//isSliceColumn bool
-	//isStarNameColumn bool
-
 	row, err := q.Get(key)
 
 	if err != nil {

src/gossie/cursor_test.go

@@ -14,7 +14,7 @@ todo:
 */
 
 type ReasonableOne struct {
-	Username string `cf:"Reasonable" key:"Username" col:"TweetID,*name" val:"*value"`
+	Username string `cf:"Reasonable" key:"Username,TweetID"`
 	TweetID  int64
 	Lat      float32
 	Lon      float32