Added tests

.github/workflows/tests.yml

@@ -21,4 +21,4 @@ jobs:
       run: go mod download
 
     - name: Run tests
-      run: go test ./... -count=1
+      run: go test ./... -count=1 -v

go.mod

@@ -7,5 +7,6 @@ require github.com/stretchr/testify v1.9.0
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	golang.org/x/exp v0.0.0-20240909161429-701f63a606c0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -4,6 +4,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+golang.org/x/exp v0.0.0-20240909161429-701f63a606c0 h1:e66Fs6Z+fZTbFBAxKfP3PALWBtpfqks2bwGcexMxgtk=
+golang.org/x/exp v0.0.0-20240909161429-701f63a606c0/go.mod h1:2TbTHSBQa924w8M6Xs1QcRcFwyucIwBGpK1p2f1YFFY=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

hnsw.go

@@ -7,6 +7,7 @@ package hnswgo
 */
 import "C"
 import (
+	"errors"
 	"fmt"
 	"math"
 	"unsafe"
@@ -15,13 +16,27 @@ import (
 type Index struct {
 	index      C.HNSW
 	dimensions int
+	size       uint32
 	normalize  bool
 	spaceType  string
 }
 
 // Returns the last error message. Returns nil if there is no error message.
-func getLastErrorMsg() string {
-	return C.GoString(C.getLastErrorMsg())
+func peekLastError() error {
+	err := C.peekLastErrorMsg()
+	if err == nil {
+		return nil
+	}
+	return errors.New(C.GoString(err))
+}
+
+// Returns and clears the last error message. Returns nil if there is no error message.
+func getLastError() error {
+	err := C.getLastErrorMsg()
+	if err == nil {
+		return nil
+	}
+	return errors.New(C.GoString(err))
 }
 
 /*
@@ -60,9 +75,23 @@ Returns a reference to an instance of an HNSW index.
 Returns an instance of an HNSW index, or an error if there was a problem initializing the index.
 */
 func New(dim int, m int, efConstruction int, randSeed int, maxElements uint32, spaceType string) (*Index, error) {
+	if dim < 1 {
+		return nil, errors.New("dimension must be >= 1")
+	}
+	if maxElements < 1 {
+		return nil, errors.New("max elements must be >= 1")
+	}
+	if m < 2 {
+		return nil, errors.New("m must be >= 2")
+	}
+	if efConstruction < 0 {
+		return nil, errors.New("efConstruction must be >= 0")
+	}
+
 	index := new(Index)
 	index.dimensions = dim
 	index.spaceType = spaceType
+	index.size = maxElements
 
 	if spaceType == "ip" {
 		index.index = C.initHNSW(C.int(dim), C.ulong(maxElements), C.int(m), C.int(efConstruction), C.int(randSeed), C.char('i'))
@@ -74,10 +103,10 @@ func New(dim int, m int, efConstruction int, randSeed int, maxElements uint32, s
 	}
 
 	if index.index == nil {
-		return nil, fmt.Errorf("failed to initialize HNSW index: %s", getLastErrorMsg())
+		return nil, getLastError()
 	}
 
-	return index, nil
+	return index, getLastError()
 }
 
 /*
@@ -94,11 +123,16 @@ Adds a vector to the HNSW index.
 
 - label:        the vector's label
 */
-func (i *Index) InsertVector(vector []float32, label uint32) {
+func (i *Index) InsertVector(vector []float32, label uint32) error {
+	if len(vector) != i.dimensions {
+		return fmt.Errorf("the vector you are trying to insert is %d-dimensional whereas your index is %d-dimensional", len(vector), i.dimensions)
+	}
+
 	if i.normalize {
 		Normalize(vector)
 	}
 	C.insertVector(i.index, (*C.float)(unsafe.Pointer(&vector[0])), C.ulong(label))
+	return getLastError()
 }
 
 /*
@@ -111,6 +145,13 @@ Performs similarity search on the HNSW index.
 Returns the labels and distances of each of the nearest neighbors. Note: the size of both arrays can be < k if k > num of vectors in the index
 */
 func (i *Index) SearchKNN(vector []float32, k int) ([]uint32, []float32, error) {
+	if len(vector) != i.dimensions {
+		return nil, nil, fmt.Errorf("the query vector is %d-dimensional whereas your index is %d-dimensional", len(vector), i.dimensions)
+	}
+	if k < 1 || uint32(k) > i.size {
+		return nil, nil, fmt.Errorf("1 <= k <= index max size")
+	}
+
 	if i.normalize {
 		Normalize(vector)
 	}
@@ -121,7 +162,7 @@ func (i *Index) SearchKNN(vector []float32, k int) ([]uint32, []float32, error)
 	numResult := int(C.searchKNN(i.index, (*C.float)(unsafe.Pointer(&vector[0])), C.int(k), &Clabel[0], &Cdist[0])) // perform the search
 
 	if numResult < 0 {
-		return nil, nil, fmt.Errorf("an error occured with the HNSW algorithm: %s", getLastErrorMsg())
+		return nil, nil, fmt.Errorf("an error occured with the HNSW algorithm: %s", getLastError())
 	}
 
 	labels := make([]uint32, k)
@@ -131,16 +172,20 @@ func (i *Index) SearchKNN(vector []float32, k int) ([]uint32, []float32, error)
 		dists[i] = float32(Cdist[i])
 	}
 
-	return labels[:numResult], dists[:numResult], nil
+	return labels[:numResult], dists[:numResult], getLastError()
 }
 
 /*
 Set's the efConstruction parameter in the HNSW index.
 
 - efConstruction: the new efConstruction parameter
 */
-func (i *Index) SetEfConstruction(efConstruction int) {
+func (i *Index) SetEfConstruction(efConstruction int) error {
+	if efConstruction < 0 {
+		return errors.New("efConstruction must be >= 0")
+	}
 	C.setEf(i.index, C.int(efConstruction))
+	return getLastError()
 }
 
 //func Load(location string, dim int, spaceType string) *HNSW {

hnsw_wrapper.cpp

@@ -1,4 +1,4 @@
-#include "hnswlib/hnswlib.h"
+#include "lib/hnswlib/hnswlib.h"
 #include "hnsw_wrapper.h"
 
 static thread_local std::string lastErrorMsg; // stores the last error message
@@ -8,10 +8,21 @@ static thread_local std::string lastErrorMsg; // stores the last error message
  * 
  * @return last error message or a null pointer
  */
-char* getLastErrorMsg() {
+char* peekLastErrorMsg() {
     return lastErrorMsg.empty() ? nullptr : strdup(lastErrorMsg.c_str());
 }
 
+/**
+ * Returns the last error message AND clears it, if there exists one. If no error message exists, a null pointer will be returned.
+ * 
+ * @return last error message or a null pointer
+ */
+char* getLastErrorMsg() {
+    char *err = peekLastErrorMsg();
+    lastErrorMsg.clear();
+    return err;
+}
+
 /**
  * Instantiates and returns an HNSW index.
  *
@@ -20,13 +31,11 @@ char* getLastErrorMsg() {
  * @param m:                `m` parameter in the HNSW algorithm
  * @param efConstruction:   `efConstruction` parameter in the HNSW algorithm
  * @param randSeed:         random seed
- * @param spaceType:        similarity metric to use in the index
+ * @param spaceType:        similarity metric to use in the index ("l" = L2, "i" = IP, "c" = cosine). (default: "l")
  * 
  * @return                  instance of a HNSW index
  */
 HNSW initHNSW(int dim, unsigned long int maxElements, int m, int efConstruction, int randSeed, char spaceType) {
-    // add checks on all arguments with specific exceptions thrown
-
     try {
         hnswlib::SpaceInterface<float> *vectorSpace;
         if (spaceType == 'i') { // inner product
@@ -64,6 +73,7 @@ void freeHNSW(HNSW hnswIndex) {
  * @param label:        the vector's label
  */
 void insertVector(HNSW hnswIndex, float *vector, unsigned long int label) {
+    // ** I believe a vector is overwritten when you insert another vector with the same label **
     try {
         ((hnswlib::HierarchicalNSW<float>*) hnswIndex)->addPoint(vector, label);
     } catch(const std::runtime_error e) {
@@ -88,20 +98,23 @@ int searchKNN(HNSW hnswIndex, float *vector, int k, unsigned long int *labels, f
     std::priority_queue<std::pair<float, hnswlib::labeltype>> searchResults;
     try {
         searchResults = ((hnswlib::HierarchicalNSW<float>*) hnswIndex)->searchKnn(vector, k);
+
+        int n = searchResults.size();
+        std::pair<float, hnswlib::labeltype> pair;
+        for (int i = n - 1; i >= 0; i--) {
+            pair = searchResults.top();
+            distances[i] = pair.first;
+            labels[i] = pair.second;
+            searchResults.pop();
+        }
+        return n;
+    } catch (const std::runtime_error e) {
+        lastErrorMsg = std::string(e.what());
+        return -1;
     } catch (const std::exception e) {
         lastErrorMsg = std::string(e.what());
         return -1;
     }
-
-    int n = searchResults.size();
-    std::pair<float, hnswlib::labeltype> pair;
-    for (int i = n - 1; i >= 0; i--) {
-        pair = searchResults.top();
-        distances[i] = pair.first;
-        labels[i] = pair.second;
-        searchResults.pop();
-    }
-    return n;
 }
 
 /**

hnsw_wrapper.h

@@ -2,6 +2,7 @@
 extern "C" {
 #endif
     typedef void* HNSW;
+    char* peekLastErrorMsg();
     char* getLastErrorMsg();
     HNSW initHNSW(int dim, unsigned long int maxElements, int m, int efConstruction, int randSeed, char simMetric);
     void freeHNSW(HNSW hnswIndex);