delta-sync/dist/core/CloudCoordinator.js

A lightweight framework for bi-directional database synchronization with automatic version tracking and conflict resolution.

// CloudCoordinator.ts
// 云端的协调层
export class CloudCoordinator {
    constructor(cloudAdapter) {
        this.CHANGES_STORE = 'cloud_synced_changes'; // 所有变更的存储
        this.ATTACHMENT_CHANGES_STORE = 'cloud_attachment_changes'; // 新增附件变更表
        this.cloudAdapter = cloudAdapter;
    }
    // 处理来自客户端的同步请求
    async applyChanges(changes) {
        try {
            // 获取服务器当前时间戳作为版本号
            const serverTimestamp = Date.now();
            const updatedChanges = changes.map(change => ({
                ...change,
                _version: serverTimestamp
            }));
            await this.cloudAdapter.putBulk(this.CHANGES_STORE, updatedChanges);
            return {
                success: true,
                processed: changes.length,
                version: serverTimestamp, // 使用服务器时间戳作为版本号
                changes: updatedChanges // 可选：返回更新后的变更记录
            };
        }
        catch (error) {
            console.error('处理同步请求时出错:', error);
            return {
                success: false,
                error: this.getErrorMessage(error)
            };
        }
    }
    async applyAttachmentChanges(changes) {
        try {
            await this.cloudAdapter.putBulk(this.ATTACHMENT_CHANGES_STORE, changes);
            const latestVersion = await this.getLatestVersion();
            return {
                success: true,
                processed: changes.length,
                version: latestVersion, // 使用实际的最新版本号
                info: {
                    attachments_processed: changes.length
                }
            };
        }
        catch (error) {
            return {
                success: false,
                error: this.getErrorMessage(error)
            };
        }
    }
    async getAttachmentChanges(since) {
        const result = await this.cloudAdapter.readByVersion(this.ATTACHMENT_CHANGES_STORE, { since });
        return result.items;
    }
    // 处理来自客户端的拉取请求（使用 since 参数表示最小版本号）
    async getPendingChanges(since) {
        try {
            const result = await this.cloudAdapter.readByVersion(this.CHANGES_STORE, { since });
            console.log("从云端读取更新成功", result);
            const latestVersion = await this.getLatestVersion();
            return {
                success: true,
                changes: result.items,
                version: latestVersion,
            };
        }
        catch (error) {
            console.error('获取变更失败:', error);
            return {
                success: false,
                error: this.getErrorMessage(error)
            };
        }
    }
    // 辅助方法，在结果中附加详细错误
    getErrorMessage(error) {
        if (error instanceof Error) {
            return error.message;
        }
        else if (typeof error === 'string') {
            return error;
        }
        else if (error && typeof error === 'object' && 'message' in error) {
            return String(error.message);
        }
        return '未知错误';
    }
    // 获取最新变更的版本号(优化查询方式)
    async getLatestVersion() {
        try {
            const result = await this.cloudAdapter.readByVersion(this.CHANGES_STORE, {
                limit: 1,
                order: 'desc' // 直接使用倒序排列
            });
            if (result.items.length > 0 && result.items[0]._version !== undefined) {
                return result.items[0]._version;
            }
            return 0;
        }
        catch (error) {
            console.error('获取最新版本号失败:', error);
            return 0;
        }
    }
}