100 lines
2.7 KiB
JavaScript
100 lines
2.7 KiB
JavaScript
class GroupManager {
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constructor() {
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this.groups = new Map(); // groupId -> Set<pieceId>
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this.pieceToGroup = new Map(); // pieceId -> groupId
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this._nextId = 1;
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}
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createSingletonGroup(pieceId) {
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const gid = this._nextId++;
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this.groups.set(gid, new Set([pieceId]));
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this.pieceToGroup.set(pieceId, gid);
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return gid;
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}
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getGroupId(pieceId) {
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return this.pieceToGroup.get(pieceId) ?? null;
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}
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/** Returns the Set<pieceId> for the group containing pieceId, or null. */
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getGroup(pieceId) {
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const gid = this.getGroupId(pieceId);
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if (gid === null) return null;
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return this.groups.get(gid) ?? null;
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}
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/** Returns all piece IDs in the same group as pieceId (including itself). */
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getPeersOf(pieceId) {
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return this.getGroup(pieceId) ?? new Set([pieceId]);
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}
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/**
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* Merge the groups containing pieceIdA and pieceIdB into a single new group.
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* @returns {number} the new group ID
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*/
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merge(pieceIdA, pieceIdB) {
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const gidA = this.getGroupId(pieceIdA);
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const gidB = this.getGroupId(pieceIdB);
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if (gidA === null || gidB === null) return gidA ?? gidB;
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if (gidA === gidB) return gidA; // already in the same group
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const newGid = this._nextId++;
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const members = new Set([...this.groups.get(gidA), ...this.groups.get(gidB)]);
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this.groups.delete(gidA);
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this.groups.delete(gidB);
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this.groups.set(newGid, members);
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members.forEach(id => this.pieceToGroup.set(id, newGid));
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return newGid;
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}
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/** Total number of distinct locked groups. */
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get groupCount() {
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return this.groups.size;
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}
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/** Total number of tracked pieces. */
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get pieceCount() {
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return this.pieceToGroup.size;
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}
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/**
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* Serialize to a plain array of arrays for localStorage.
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* @returns {number[][]}
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*/
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serialize() {
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return Array.from(this.groups.values()).map(set => Array.from(set));
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}
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/**
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* Replace all internal state from a serialized groups array.
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* Used for applying remote state updates.
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* @param {number[][]} groupsList
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*/
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rebuildFromGroups(groupsList) {
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this.groups.clear();
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this.pieceToGroup.clear();
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this._nextId = 1;
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groupsList.forEach(members => {
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const gid = this._nextId++;
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const set = new Set(members);
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this.groups.set(gid, set);
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members.forEach(id => this.pieceToGroup.set(id, gid));
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});
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}
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/**
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* Rebuild from serialized data.
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* @param {number[][]} groupsList
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*/
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static deserialize(groupsList) {
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const gm = new GroupManager();
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groupsList.forEach(members => {
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const gid = gm._nextId++;
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const set = new Set(members);
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gm.groups.set(gid, set);
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members.forEach(id => gm.pieceToGroup.set(id, gid));
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});
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return gm;
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}
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}
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