feat: WhereDocument filter with $and, $or, $contains and $not_contain…

…s filters

collection.go

@@ -5,7 +5,6 @@ import (
 	"errors"
 	"fmt"
 	"path/filepath"
-	"slices"
 	"sync"
 )
 
@@ -64,7 +63,7 @@ type QueryOptions struct {
 	Where map[string]string
 
 	// Conditional filtering on documents.
-	WhereDocument map[string]string
+	WhereDocuments []WhereDocument
 
 	// Negative is the negative query options.
 	// They can be used to exclude certain results from the query.
@@ -296,19 +295,19 @@ func (c *Collection) AddDocument(ctx context.Context, doc Document) error {
 //   - where: Conditional filtering on metadata. Optional.
 //   - whereDocument: Conditional filtering on documents. Optional.
 //   - ids: The ids of the documents to delete. If empty, all documents are deleted.
-func (c *Collection) Delete(_ context.Context, where, whereDocument map[string]string, ids ...string) error {
+func (c *Collection) Delete(_ context.Context, where map[string]string, whereDocuments []WhereDocument, ids ...string) error {
 	// must have at least one of where, whereDocument or ids
-	if len(where) == 0 && len(whereDocument) == 0 && len(ids) == 0 {
+	if len(where) == 0 && len(whereDocuments) == 0 && len(ids) == 0 {
 		return fmt.Errorf("must have at least one of where, whereDocument or ids")
 	}
 
 	if len(c.documents) == 0 {
 		return nil
 	}
 
-	for k := range whereDocument {
-		if !slices.Contains(supportedFilters, k) {
-			return errors.New("unsupported whereDocument operator")
+	for _, whereDocument := range whereDocuments {
+		if err := whereDocument.Validate(); err != nil {
+			return fmt.Errorf("invalid whereDocument %#v: %w", whereDocument, err)
 		}
 	}
 
@@ -317,9 +316,9 @@ func (c *Collection) Delete(_ context.Context, where, whereDocument map[string]s
 	c.documentsLock.Lock()
 	defer c.documentsLock.Unlock()
 
-	if where != nil || whereDocument != nil {
+	if where != nil || len(whereDocuments) > 0 {
 		// metadata + content filters
-		filteredDocs := filterDocs(c.documents, where, whereDocument)
+		filteredDocs := filterDocs(c.documents, where, whereDocuments)
 		for _, doc := range filteredDocs {
 			docIDs = append(docIDs, doc.ID)
 		}
@@ -376,7 +375,7 @@ type Result struct {
 //     There can be fewer results if a filter is applied.
 //   - where: Conditional filtering on metadata. Optional.
 //   - whereDocument: Conditional filtering on documents. Optional.
-func (c *Collection) Query(ctx context.Context, queryText string, nResults int, where, whereDocument map[string]string) ([]Result, error) {
+func (c *Collection) Query(ctx context.Context, queryText string, nResults int, where map[string]string, whereDocument []WhereDocument) ([]Result, error) {
 	if queryText == "" {
 		return nil, errors.New("queryText is empty")
 	}
@@ -432,7 +431,7 @@ func (c *Collection) QueryWithOptions(ctx context.Context, options QueryOptions)
 		}
 	}
 
-	result, err := c.queryEmbedding(ctx, queryVector, negativeVector, negativeFilterThreshold, options.NResults, options.Where, options.WhereDocument)
+	result, err := c.queryEmbedding(ctx, queryVector, negativeVector, negativeFilterThreshold, options.NResults, options.Where, options.WhereDocuments)
 	if err != nil {
 		return nil, err
 	}
@@ -449,12 +448,12 @@ func (c *Collection) QueryWithOptions(ctx context.Context, options QueryOptions)
 //     There can be fewer results if a filter is applied.
 //   - where: Conditional filtering on metadata. Optional.
 //   - whereDocument: Conditional filtering on documents. Optional.
-func (c *Collection) QueryEmbedding(ctx context.Context, queryEmbedding []float32, nResults int, where, whereDocument map[string]string) ([]Result, error) {
-	return c.queryEmbedding(ctx, queryEmbedding, nil, 0, nResults, where, whereDocument)
+func (c *Collection) QueryEmbedding(ctx context.Context, queryEmbedding []float32, nResults int, where map[string]string, whereDocuments []WhereDocument) ([]Result, error) {
+	return c.queryEmbedding(ctx, queryEmbedding, nil, 0, nResults, where, whereDocuments)
 }
 
 // queryEmbedding performs an exhaustive nearest neighbor search on the collection.
-func (c *Collection) queryEmbedding(ctx context.Context, queryEmbedding, negativeEmbeddings []float32, negativeFilterThreshold float32, nResults int, where, whereDocument map[string]string) ([]Result, error) {
+func (c *Collection) queryEmbedding(ctx context.Context, queryEmbedding, negativeEmbeddings []float32, negativeFilterThreshold float32, nResults int, where map[string]string, whereDocuments []WhereDocument) ([]Result, error) {
 	if len(queryEmbedding) == 0 {
 		return nil, errors.New("queryEmbedding is empty")
 	}
@@ -472,14 +471,14 @@ func (c *Collection) queryEmbedding(ctx context.Context, queryEmbedding, negativ
 	}
 
 	// Validate whereDocument operators
-	for k := range whereDocument {
-		if !slices.Contains(supportedFilters, k) {
-			return nil, errors.New("unsupported operator")
+	for _, whereDocument := range whereDocuments {
+		if err := whereDocument.Validate(); err != nil {
+			return nil, fmt.Errorf("invalid whereDocument %#v: %w", whereDocument, err)
 		}
 	}
 
 	// Filter docs by metadata and content
-	filteredDocs := filterDocs(c.documents, where, whereDocument)
+	filteredDocs := filterDocs(c.documents, where, whereDocuments)
 
 	// No need to continue if the filters got rid of all documents
 	if len(filteredDocs) == 0 {

collection_test.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"slices"
 	"strconv"
+	"strings"
 	"testing"
 )
 
@@ -372,10 +373,10 @@ func TestCollection_QueryError(t *testing.T) {
 		{
 			name: "Bad content filter",
 			query: func() error {
-				_, err := c.Query(context.Background(), "foo", 1, nil, map[string]string{"invalid": "foo"})
+				_, err := c.Query(context.Background(), "foo", 1, nil, []WhereDocument{{Operator: "invalid", Value: "foo"}})
 				return err
 			},
-			expErr: "unsupported operator",
+			expErr: "unsupported where document operator invalid",
 		},
 	}
 
@@ -384,7 +385,7 @@ func TestCollection_QueryError(t *testing.T) {
 			err := tc.query()
 			if err == nil {
 				t.Fatal("expected error, got nil")
-			} else if err.Error() != tc.expErr {
+			} else if !strings.Contains(err.Error(), tc.expErr) {
 				t.Fatal("expected", tc.expErr, "got", err)
 			}
 		})
@@ -502,7 +503,7 @@ func TestCollection_Delete(t *testing.T) {
 	checkCount(1)
 
 	// Test 3 - Remove document by content
-	err = c.Delete(context.Background(), nil, map[string]string{"$contains": "hallo welt"})
+	err = c.Delete(context.Background(), nil, []WhereDocument{WhereDocument{Operator: WhereDocumentOperatorContains, Value: "hallo welt"}})
 	if err != nil {
 		t.Fatal("expected nil, got", err)
 	}

query.go

@@ -11,8 +11,6 @@ import (
 	"sync"
 )
 
-var supportedFilters = []string{"$contains", "$not_contains"}
-
 type docSim struct {
 	docID      string
 	similarity float32
@@ -84,7 +82,7 @@ func (d *maxDocSims) values() []docSim {
 
 // filterDocs filters a map of documents by metadata and content.
 // It does this concurrently.
-func filterDocs(docs map[string]*Document, where, whereDocument map[string]string) []*Document {
+func filterDocs(docs map[string]*Document, where map[string]string, whereDocuments []WhereDocument) []*Document {
 	filteredDocs := make([]*Document, 0, len(docs))
 	filteredDocsLock := sync.Mutex{}
 
@@ -104,7 +102,7 @@ func filterDocs(docs map[string]*Document, where, whereDocument map[string]strin
 		go func() {
 			defer wg.Done()
 			for doc := range docChan {
-				if documentMatchesFilters(doc, where, whereDocument) {
+				if documentMatchesFilters(doc, where, whereDocuments) {
 					filteredDocsLock.Lock()
 					filteredDocs = append(filteredDocs, doc)
 					filteredDocsLock.Unlock()
@@ -128,9 +126,84 @@ func filterDocs(docs map[string]*Document, where, whereDocument map[string]strin
 	return filteredDocs
 }
 
+type WhereDocumentOperator string
+
+const (
+	WhereDocumentOperatorContains    WhereDocumentOperator = "$contains"
+	WhereDocumentOperatorNotContains WhereDocumentOperator = "$not_contains"
+	WhereDocumentOperatorOr          WhereDocumentOperator = "$or"
+	WhereDocumentOperatorAnd         WhereDocumentOperator = "$and"
+)
+
+type WhereDocument struct {
+	Operator       WhereDocumentOperator
+	Value          string
+	WhereDocuments []WhereDocument
+}
+
+func (wd *WhereDocument) Validate() error {
+
+	if !slices.Contains([]WhereDocumentOperator{WhereDocumentOperatorContains, WhereDocumentOperatorNotContains}, wd.Operator) {
+		return fmt.Errorf("unsupported where document operator %s", wd.Operator)
+	}
+
+	if wd.Operator == "" {
+		return fmt.Errorf("where document operator is empty")
+	}
+
+	// $contains and $not_contains require a string value
+	if slices.Contains([]WhereDocumentOperator{WhereDocumentOperatorContains, WhereDocumentOperatorNotContains}, wd.Operator) {
+		if wd.Value == "" {
+			return fmt.Errorf("where document operator %s requires a value", wd.Operator)
+		}
+	}
+
+	// $or requires sub-filters
+	if slices.Contains([]WhereDocumentOperator{WhereDocumentOperatorOr, WhereDocumentOperatorAnd}, wd.Operator) {
+		if len(wd.WhereDocuments) == 0 {
+			return fmt.Errorf("where document operator %s must have at least one sub-filter", wd.Operator)
+		}
+	}
+
+	for _, wd := range wd.WhereDocuments {
+		if err := wd.Validate(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// Matches checks if a document matches the WhereDocument filter(s)
+// There is no error checking on the WhereDocument struct, so it must be validated before calling this function.
+func (wd *WhereDocument) Matches(doc *Document) bool {
+	switch wd.Operator {
+	case WhereDocumentOperatorContains:
+		return strings.Contains(doc.Content, wd.Value)
+	case WhereDocumentOperatorNotContains:
+		return !strings.Contains(doc.Content, wd.Value)
+	case WhereDocumentOperatorOr:
+		for _, subFilter := range wd.WhereDocuments {
+			if subFilter.Matches(doc) {
+				return true
+			}
+		}
+		return false
+	case WhereDocumentOperatorAnd:
+		for _, subFilter := range wd.WhereDocuments {
+			if !subFilter.Matches(doc) {
+				return false
+			}
+		}
+		return true
+	default:
+		return false
+	}
+}
+
 // documentMatchesFilters checks if a document matches the given filters.
-// When calling this function, the whereDocument keys must already be validated!
-func documentMatchesFilters(document *Document, where, whereDocument map[string]string) bool {
+// When calling this function, the whereDocument structs must already be validated!
+func documentMatchesFilters(document *Document, where map[string]string, whereDocuments []WhereDocument) bool {
 	// A document's metadata must have *all* the fields in the where clause.
 	for k, v := range where {
 		// TODO: Do we want to check for existence of the key? I.e. should
@@ -141,21 +214,10 @@ func documentMatchesFilters(document *Document, where, whereDocument map[string]
 		}
 	}
 
-	// A document must satisfy *all* filters, until we support the `$or` operator.
-	for k, v := range whereDocument {
-		switch k {
-		case "$contains":
-			if !strings.Contains(document.Content, v) {
-				return false
-			}
-		case "$not_contains":
-			if strings.Contains(document.Content, v) {
-				return false
-			}
-		default:
-			// No handling (error) required because we already validated the
-			// operators. This simplifies the concurrency logic (no err var
-			// and lock, no context to cancel).
+	// A document must satisfy *all* WhereDocument filters (that's basically a top-level $and operator)
+	for _, whereDocument := range whereDocuments {
+		if !whereDocument.Matches(document) {
+			return false
 		}
 	}