Prefix matching on frontend

frontend/dispatcher.go

@@ -47,6 +47,8 @@ func handler(w http.ResponseWriter, r *http.Request) {
 		err = httpInfo(w, operation)
 	case OpDelete:
 		err = httpDelete(w, operation)
+	case OpPrefixMatch:
+		err = httpMatch(w, operation)
 	default:
 		err = &HTTPError{Message: "I don't get what you're trying to do", Code: 400}
 	}

frontend/goleg/highlevel.go

@@ -59,6 +59,7 @@ func (d Database) Squish() bool {
 	return CSquish(d.db) == 1
 }
 
-func (d Database) PrefixMatch(prefix string) []string {
-	return CPrefixMatch(d.db, prefix, uintptr(len(prefix)))
+func (d Database) PrefixMatch(prefix string) (bool, []string) {
+	len, out := CPrefixMatch(d.db, prefix, uintptr(len(prefix)))
+	return len >= 0, out
 }

frontend/goleg/wrapper.go

@@ -188,27 +188,34 @@ func CCas(db *C.ol_database, key string, klen uintptr, value []byte, vsize uintp
 	return int(C.ol_cas(db, ckey, cklen, cvalue, cvsize, covalue, covsize))
 }
 
-func CPrefixMatch(db *C.ol_database, prefix string, plen uintptr) []string {
+func CPrefixMatch(db *C.ol_database, prefix string, plen uintptr) (int, []string) {
 	// Turn parameters into their C counterparts
 	cprefix := C.CString(prefix)
 	defer C.free(unsafe.Pointer(cprefix))
 
 	cplen := (C.size_t)(plen)
 
-	var ptr *C.ol_val_array
-	length := int(C.ol_prefix_match(db, cprefix, cplen, ptr))
+	// Call native function
+	var ptr C.ol_val_array
+	length := int(C.ol_prefix_match(db, cprefix, cplen, &ptr))
+	if length < 0 {
+		return length, nil
+	}
 
+	// Set array structure
 	hdr := reflect.SliceHeader{
 		Data: uintptr(unsafe.Pointer(ptr)),
 		Len:  length,
 		Cap:  length,
 	}
 	strSlice := *(*[]*C.char)(unsafe.Pointer(&hdr))
+	// Create GoString array
 	out := make([]string, 0)
 	for i := range strSlice {
 		out = append(out, C.GoString(strSlice[i]))
 		C.free(unsafe.Pointer(strSlice[i]))
 	}
+	// Free structure
 	C.free(unsafe.Pointer(ptr))
-	return out
+	return length, out
 }

frontend/operations.go

@@ -5,6 +5,7 @@ import (
 	"io/ioutil"
 	"net/http"
 	"strconv"
+	"strings"
 	"time"
 )
 
@@ -17,7 +18,7 @@ const (
 	OpCursorLast  = "_last"
 	OpCursorNext  = "._next"
 	OpCursorPrev  = "._prev"
-	OpPrefixMatch = "_match"
+	OpPrefixMatch = "._match"
 )
 
 func httpGet(w http.ResponseWriter, op Operation) *HTTPError {
@@ -97,3 +98,16 @@ func httpDelete(w http.ResponseWriter, op Operation) *HTTPError {
 	fmt.Fprintf(w, "Key deleted successfully!")
 	return nil
 }
+
+func httpMatch(w http.ResponseWriter, op Operation) *HTTPError {
+	has, res := op.Database.PrefixMatch(op.Key)
+	if !has {
+		return &HTTPError{Code: 500, Message: "Something went horribly wrong..."}
+	}
+	if len(res) == 0 {
+		return &HTTPError{Code: 404, Message: "No matches found"}
+	}
+
+	fmt.Fprintf(w, strings.Join(res, "\n"))
+	return nil
+}