From 48ee419f377e32b2e19f39c4bc4270e53f03d134 Mon Sep 17 00:00:00 2001
From: ryan-awad <ryanawad@yahoo.com>
Date: Tue, 1 Oct 2024 15:21:34 -0400
Subject: [PATCH] Handling file permission and existance errors

---
 hnsw.go              | 19 ++++++++++
 tests/hnswgo_test.go | 84 +++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 102 insertions(+), 1 deletion(-)

diff --git a/hnsw.go b/hnsw.go
index 2c6134f..c4c7efb 100644
--- a/hnsw.go
+++ b/hnsw.go
@@ -10,6 +10,7 @@ import (
 	"errors"
 	"fmt"
 	"math"
+	"os"
 	"unsafe"
 )
 
@@ -130,6 +131,11 @@ func LoadIndex(location string, dim int, spaceType string, maxElements uint32) (
 		return nil, errors.New("max elements must be >= 1")
 	}
 
+	// checking the location's validity and permissions
+	if _, err := os.ReadFile(location); err != nil {
+		return nil, err
+	}
+
 	index := new(Index)
 	index.dimensions = dim
 	index.spaceType = spaceType
@@ -165,6 +171,19 @@ func (i *Index) SaveToDisk(location string) error {
 	if location == "" {
 		return errors.New("location cannot be blank")
 	}
+
+	// checking the location's validity and permissions
+	if _, err := os.Stat(location); os.IsNotExist(err) { // file does not exist yet
+		if _, err := os.Create(location); err != nil {
+			return err
+		}
+		if err := os.Remove(location); err != nil {
+			return err
+		}
+	} else if os.IsPermission(err) {
+		return err
+	}
+
 	cLocation := C.CString(location)
 	defer C.free(unsafe.Pointer(cLocation))
 	C.saveHNSW(i.index, cLocation)
diff --git a/tests/hnswgo_test.go b/tests/hnswgo_test.go
index abeb5d7..b11fda4 100644
--- a/tests/hnswgo_test.go
+++ b/tests/hnswgo_test.go
@@ -497,6 +497,76 @@ func TestSaveToDiskEmptyPath(t *testing.T) {
 	}
 }
 
+func TestSaveToDiskInvalidPath(t *testing.T) {
+	index, err := setup()
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+	defer index.Free()
+
+	// sample vectors
+	vectors := [][]float32{
+		{1.2, 3.4},
+		{2.1, 4.5},
+		{0.5, 1.7},
+		{3.3, 2.2},
+		{4.8, 5.6},
+		{7.1, 8.2},
+		{9.0, 0.4},
+		{6.3, 3.5},
+		{2.9, 7.8},
+		{5.0, 1.1},
+	}
+
+	// insert sample vectors
+	for i, v := range vectors {
+		if err := index.InsertVector(v, uint64(i)); err != nil {
+			t.Fatalf("An error occured when inserting vector %v: %s", v, err.Error())
+		}
+	}
+
+	if err := index.SaveToDisk("/some/fake/path/index.bin"); err == nil {
+		t.Fatal("No error occured when setting the location to an invalid path")
+	} else if !os.IsNotExist(err) {
+		t.Fatalf("Unexpected error received: %s", err.Error())
+	}
+}
+
+func TestSaveToDiskInvalidPerms(t *testing.T) {
+	index, err := setup()
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+	defer index.Free()
+
+	// sample vectors
+	vectors := [][]float32{
+		{1.2, 3.4},
+		{2.1, 4.5},
+		{0.5, 1.7},
+		{3.3, 2.2},
+		{4.8, 5.6},
+		{7.1, 8.2},
+		{9.0, 0.4},
+		{6.3, 3.5},
+		{2.9, 7.8},
+		{5.0, 1.1},
+	}
+
+	// insert sample vectors
+	for i, v := range vectors {
+		if err := index.InsertVector(v, uint64(i)); err != nil {
+			t.Fatalf("An error occured when inserting vector %v: %s", v, err.Error())
+		}
+	}
+
+	if err := index.SaveToDisk("/tmp/perm_test/index.bin"); err == nil {
+		t.Fatal("No error occured when setting the location to a path with elevated permissions")
+	} else if !os.IsPermission(err) {
+		t.Fatalf("Unexpected error received: %s", err.Error())
+	}
+}
+
 func TestLoadIndexSuccess(t *testing.T) {
 	index, err := hnswgo.LoadIndex("/tmp/saved_data.bin", 2, "l2", uint32(10000)) // same as whats in setup()
 	if err != nil {
@@ -540,7 +610,19 @@ func TestLoadIndexInvalidPath(t *testing.T) {
 	}
 	if err == nil {
 		t.Fatal("No error occured when trying to load an index with a fake location.")
-	} else if err.Error() != "Cannot open file" {
+	} else if !os.IsNotExist(err) {
+		t.Fatalf("Unexpected error received: %s", err.Error())
+	}
+}
+
+func TestLoadIndexInvalidPerms(t *testing.T) {
+	index, err := hnswgo.LoadIndex("/root/index.bin", 2, "l2", uint32(10000))
+	if index != nil {
+		defer index.Free()
+	}
+	if err == nil {
+		t.Fatal("No error occured when trying to load an index with a fake location.")
+	} else if !os.IsPermission(err) {
 		t.Fatalf("Unexpected error received: %s", err.Error())
 	}
 }