From b4e6dd77812bdba5bc83f5b5d4e9be452afeb0cb Mon Sep 17 00:00:00 2001
From: Dominik Tomasi <dominik.tomasi@gmail.com>
Date: Tue, 20 Feb 2024 18:31:29 +0100
Subject: [PATCH] feat: add method that returns all vertices

Signed-off-by: Dominik Tomasi <dominik.tomasi@gmail.com>
---
 directed.go   |  4 ++++
 graph.go      |  3 +++
 store.go      | 18 ++++++++++++++++--
 undirected.go |  4 ++++
 4 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/directed.go b/directed.go
index a044194c..1481fa64 100644
--- a/directed.go
+++ b/directed.go
@@ -75,6 +75,10 @@ func (d *directed[K, T]) RemoveVertex(hash K) error {
 	return d.store.RemoveVertex(hash)
 }
 
+func (d *directed[K, T]) Vertices() map[K]T {
+	return d.store.AllVertices()
+}
+
 func (d *directed[K, T]) AddEdge(sourceHash, targetHash K, options ...func(*EdgeProperties)) error {
 	_, _, err := d.store.Vertex(sourceHash)
 	if err != nil {
diff --git a/graph.go b/graph.go
index 9376eb5f..7609c39b 100644
--- a/graph.go
+++ b/graph.go
@@ -99,6 +99,9 @@ type Graph[K comparable, T any] interface {
 	// be returned. If the vertex doesn't exist, ErrVertexNotFound is returned.
 	RemoveVertex(hash K) error
 
+	// Vertices returns a copy of all vertices as map
+	Vertices() map[K]T
+
 	// AddEdge creates an edge between the source and the target vertex.
 	//
 	// If either vertex cannot be found, ErrVertexNotFound will be returned. If
diff --git a/store.go b/store.go
index e41a7506..0792c98b 100644
--- a/store.go
+++ b/store.go
@@ -2,6 +2,7 @@ package graph
 
 import (
 	"fmt"
+	"maps"
 	"sync"
 )
 
@@ -25,6 +26,9 @@ type Store[K comparable, T any] interface {
 	// ErrVertexHasEdges should be returned.
 	RemoveVertex(hash K) error
 
+	// AllVertices returns a map, containing all vertices
+	AllVertices() map[K]T
+
 	// ListVertices should return all vertices in the graph in a slice.
 	ListVertices() ([]K, error)
 
@@ -75,8 +79,8 @@ type memoryStore[K comparable, T any] struct {
 
 	// outEdges and inEdges store all outgoing and ingoing edges for all vertices. For O(1) access,
 	// these edges themselves are stored in maps whose keys are the hashes of the target vertices.
-	outEdges map[K]map[K]Edge[K] // source -> target
-	inEdges  map[K]map[K]Edge[K] // target -> source
+	outEdges  map[K]map[K]Edge[K] // source -> target
+	inEdges   map[K]map[K]Edge[K] // target -> source
 	edgeCount int
 }
 
@@ -103,6 +107,16 @@ func (s *memoryStore[K, T]) AddVertex(k K, t T, p VertexProperties) error {
 	return nil
 }
 
+func (s *memoryStore[K, T]) AllVertices() map[K]T {
+	out := make(map[K]T, len(s.vertices))
+	s.lock.RLock()
+	defer s.lock.RUnlock()
+
+	maps.Copy(out, s.vertices)
+
+	return out
+}
+
 func (s *memoryStore[K, T]) ListVertices() ([]K, error) {
 	s.lock.RLock()
 	defer s.lock.RUnlock()
diff --git a/undirected.go b/undirected.go
index 519526e8..80c35f0e 100644
--- a/undirected.go
+++ b/undirected.go
@@ -56,6 +56,10 @@ func (u *undirected[K, T]) RemoveVertex(hash K) error {
 	return u.store.RemoveVertex(hash)
 }
 
+func (u *undirected[K, T]) Vertices() map[K]T {
+	return u.store.AllVertices()
+}
+
 func (u *undirected[K, T]) AddEdge(sourceHash, targetHash K, options ...func(*EdgeProperties)) error {
 	if _, _, err := u.store.Vertex(sourceHash); err != nil {
 		return fmt.Errorf("could not find source vertex with hash %v: %w", sourceHash, err)