[Bug] Schema Cache expandCapacity concurrent issue

[qwtsc]

Bug Type (问题类型)

other exception / error (其他异常报错)

Before submit

• 我已经确认现有的 Issues 与 FAQ 中没有相同 / 重复问题 (I have confirmed and searched that there are no similar problems in the historical issue and documents)

Environment (环境信息)

see the following error-log

org.apache.hugegraph.exception.ServerException: Index 32 out of bounds for length 32

Expected & Actual behavior (期望与实际表现)

    public void set(int key, V value) {
        if (key >= this.currentSize) {
            this.expandCapacity();
        }
        // this.array is not the one that has done expandCapacity!
        this.array[key] = value;
    }

    private synchronized void expandCapacity() {
        if (this.currentSize == this.maxSize) {
            return;
        }
        this.currentSize = Math.min(this.currentSize * 2, this.maxSize);
        Object[] newArray = new Object[this.currentSize];
        System.arraycopy(this.array, 0, newArray, 0, this.array.length);
        this.clear();
        this.array = newArray;
    }

Vertex/Edge example (问题点 / 边数据举例)

No response

Schema [VertexLabel, EdgeLabel, IndexLabel] (元数据结构)

No response

[qwtsc]

some advice

1. use volatile
2. In expandCapacity, write this.currentSize field after write this.array, or just use this.array.length to replace this.currentSize
3. it's ok to simply use concurrentHashMap to replace this data structure.

[imbajin]

Thanks, could submit a PR including related test for it

@conghuhu free to take a look with it~

[conghuhu]

ok, plz assign to me

[imbajin]

follow-up: #2332 (comment)