Rust Google Firestore gRPC客户端库firestore_grpc的使用，支持高效NoSQL数据库操作与实时数据同步

环境变量设置

export PROJECT_ID=YOUR_PROJECT_ID
export TOKEN=`gcloud auth print-access-token`

Cargo.toml配置

[dependencies]
firestore_grpc = "0.109"
tokio = {version = "1.0", features = ["full"]}

示例代码

use firestore_grpc::tonic::{
    codegen::InterceptedService,
    metadata::MetadataValue,
    transport::{Channel, ClientTlsConfig},
    Request, Status,
};
use firestore_grpc::v1::{
    firestore_client::FirestoreClient, value::ValueType, CreateDocumentRequest, Document, Value,
};
use std::env;

const URL: &'static str = "https://firestore.googleapis.com";
const DOMAIN: &'static str = "firestore.googleapis.com";

pub type BoxError = Box<dyn std::error::Error + Sync + Send + 'static>;

fn get_token() -> String {
    env::var("TOKEN").unwrap()
}

fn get_project_id() -> String {
    env::var("PROJECT_ID").unwrap()
}

async fn get_client() -> Result<FirestoreClient<InterceptedService<Channel, impl Fn(Request<()>) -> Result<Request<()>, Status>>>, BoxError> {
    let endpoint = Channel::from_static(URL).tls_config(ClientTlsConfig::new().domain_name(DOMAIN));

    let bearer_token = format!("Bearer {}", get_token());
    let header_value = MetadataValue::from_str(&bearer_token)?;

    let channel = endpoint?.connect().await?;

    let service = FirestoreClient::with_interceptor(channel, move |mut req: Request<()>| {
        req.metadata_mut()
            .insert("authorization", header_value.clone());
        Ok(req)
    });
    Ok(service)
}

async fn create_document() -> Result<Document, BoxError> {
    let parent = format!(
        "projects/{}/databases/(default)/documents",
        get_project_id()
    );
    let collection_id = "greetings".into();
    let document_id = "".into();
    let mut fields = std.collections::HashMap::new();
    fields.insert(
        "message".into(),
        Value {
            value_type: Some(ValueType::StringValue("Hello world!".into())),
        },
    );
    let document = Some(Document {
        name: "".into(),
        fields,
        create_time: None,
        update_time: None,
    });
    let res = get_client()
        .await?
        .create_document(CreateDocumentRequest {
            parent,
            collection_id,
            document_id,
            document,
            mask: None,
        })
        .await?;
    Ok(res.into_inner())
}

#[tokio::main]
async fn main() {
    create_document().await.unwrap();
}

完整示例说明

1. 首先需要设置环境变量PROJECT_ID和TOKEN
2. 在Cargo.toml中添加依赖项
3. 代码主要功能：
   • get_token()和get_project_id()获取环境变量
   • get_client()创建Firestore gRPC客户端
   • create_document()创建新文档示例
   • 使用tokio::main宏运行异步主函数

这个示例展示了如何使用firestore_grpc库创建Firestore文档的基本操作，实际应用中还需要实现更多功能如token更新等。

完整示例代码

// 引入必要的库和模块
use firestore_grpc::tonic::{
    codegen::InterceptedService,
    metadata::MetadataValue,
    transport::{Channel, ClientTlsConfig},
    Request, Status,
};
use firestore_grpc::v1::{
    firestore_client::FirestoreClient, 
    value::ValueType, 
    CreateDocumentRequest, 
    Document, 
    Value,
    GetDocumentRequest,
    UpdateDocumentRequest,
    DeleteDocumentRequest,
    ListDocumentsRequest
};
use std::env;
use std::collections::HashMap;

// 定义常量和类型
const FIRESTORE_URL: &str = "https://firestore.googleapis.com";
const FIRESTORE_DOMAIN: &str = "firestore.googleapis.com";
pub type BoxError = Box<dyn std::error::Error + Sync + Send + 'static>;

// 获取认证token
fn get_token() -> String {
    env::var("TOKEN").expect("TOKEN环境变量未设置")
}

// 获取项目ID
fn get_project_id() -> String {
    env::var("PROJECT_ID").expect("PROJECT_ID环境变量未设置")
}

// 构建Firestore客户端
async fn get_client() -> Result<FirestoreClient<InterceptedService<Channel, impl Fn(Request<()>) -> Result<Request<()>, Status>>>, BoxError> {
    let endpoint = Channel::from_static(FIRESTORE_URL)
        .tls_config(ClientTlsConfig::new().domain_name(FIRESTORE_DOMAIN));

    let bearer_token = format!("Bearer {}", get_token());
    let header_value = MetadataValue::from_str(&bearer_token)?;

    let channel = endpoint?.connect().await?;

    let client = FirestoreClient::with_interceptor(channel, move |mut req: Request<()>| {
        req.metadata_mut()
            .insert("authorization", header_value.clone());
        Ok(req)
    });
    Ok(client)
}

// 创建文档
async fn create_document(collection: &str, data: HashMap<String, Value>) -> Result<Document, BoxError> {
    let parent = format!("projects/{}/databases/(default)/documents", get_project_id());
    
    let document = Some(Document {
        name: "".to_string(),
        fields: data,
        create_time: None,
        update_time: None,
    });
    
    let response = get_client()
        .await?
        .create_document(CreateDocumentRequest {
            parent,
            collection_id: collection.to_string(),
            document_id: "".to_string(), // 空字符串让Firestore自动生成ID
            document,
            mask: None,
        })
        .await?;
    
    Ok(response.into_inner())
}

// 获取文档
async fn get_document(document_path: &str) -> Result<Document, BoxError> {
    let response = get_client()
        .await?
        .get_document(GetDocumentRequest {
            name: document_path.to_string(),
            mask: None,
            consistency_selector: None,
        })
        .await?;
    
    Ok(response.into_inner())
}

// 更新文档
async fn update_document(document_path: &str, data: HashMap<String, Value>) -> Result<Document, BoxError> {
    let document = Document {
        name: document_path.to_string(),
        fields: data,
        create_time: None,
        update_time: None,
    };
    
    let response = get_client()
        .await?
        .update_document(UpdateDocumentRequest {
            document: Some(document),
            update_mask: None,
            mask: None,
            current_document: None,
        })
        .await?;
    
    Ok(response.into_inner())
}

// 删除文档
async fn delete_document(document_path: &str) -> Result<(), BoxError> {
    get_client()
        .await?
        .delete_document(DeleteDocumentRequest {
            name: document_path.to_string(),
            current_document: None,
        })
        .await?;
    
    Ok(())
}

// 列出集合中的文档
async fn list_documents(collection_path: &str) -> Result<Vec<Document>, BoxError> {
    let response = get_client()
        .await?
        .list_documents(ListDocumentsRequest {
            parent: collection_path.to_string(),
            collection_id: "".to_string(), // 从parent中解析
            page_size: 0,
            page_token: "".to_string(),
            order_by: "".to_string(),
            mask: None,
            show_missing: false,
            consistency_selector: None,
        })
        .await?;
    
    Ok(response.into_inner().documents)
}

#[tokio::main]
async fn main() {
    // 示例1: 创建文档
    let mut data = HashMap::new();
    data.insert("message".to_string(), Value {
        value_type: Some(ValueType::StringValue("Hello Firestore!".to_string())),
    });
    
    match create_document("test_collection", data).await {
        Ok(doc) => println!("创建文档成功: {:?}", doc),
        Err(e) => eprintln!("创建文档失败: {}", e),
    }
    
    // 示例2: 获取文档
    let doc_path = "projects/YOUR_PROJECT_ID/databases/(default)/documents/test_collection/auto_generated_id";
    match get_document(doc_path).await {
        Ok(doc) => println!("获取文档成功: {:?}", doc),
        Err(e) => eprintln!("获取文档失败: {}", e),
    }
}

完整功能说明

1. 环境配置

   • 需要设置PROJECT_ID和TOKEN环境变量
   • 在Cargo.toml中添加firestore_grpc和tokio依赖

2. 核心功能

   • get_client(): 创建经过身份验证的Firestore gRPC客户端
   • create_document(): 在指定集合中创建新文档
   • get_document(): 根据路径获取特定文档
   • update_document(): 更新现有文档
   • delete_document(): 删除指定文档
   • list_documents(): 列出集合中的所有文档

3. 使用说明

   • 所有操作都是异步的，需要使用tokio::main宏
   • 文档数据使用HashMap<String, Value>表示
   • 错误处理使用BoxError类型

4. 扩展建议

   • 实现token自动刷新机制
   • 添加文档字段验证
   • 支持更复杂的查询操作
   • 实现实时数据监听功能

这个完整示例提供了Firestore的基本CRUD操作实现，可以作为开发更复杂应用的起点。