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Object Storage Service:C上傳回調

更新時間:Nov 28, 2024

OSS在完成檔案(Object)上傳時可以提供回調(Callback)給應用伺服器。您只需要在發送給OSS的請求中攜帶相應的Callback參數,即可實現上傳回調。

注意事項

  • 本文以華東1(杭州)外網Endpoint為例。如果您希望通過與OSS同地區的其他阿里雲產品訪問OSS,請使用內網Endpoint。關於OSS支援的Region與Endpoint的對應關係,請參見OSS地區和訪問網域名稱

  • 本文以OSS網域名稱建立OSSClient為例。如果您希望通過自訂網域名、STS等方式建立OSSClient,請參見初始化

範例程式碼

以下代碼用於上傳回調:

#include "oss_api.h"
#include "aos_http_io.h"
/* yourEndpoint填寫Bucket所在地區對應的Endpoint。以華東1(杭州)為例,Endpoint填寫為https://oss-cn-hangzhou.aliyuncs.com。*/
const char *endpoint = "yourEndpoint";

/* 填寫Bucket名稱,例如examplebucket。*/
const char *bucket_name = "examplebucket";
/* 填寫Object完整路徑,完整路徑中不能包含Bucket名稱,例如exampledir/exampleobject.txt。*/
const char *object_name = "exampledir/exampleobject.txt";
const char *object_content = "More than just cloud.";
/* yourRegion填寫Bucket所在地區對應的Region。以華東1(杭州)為例,Region填寫為cn-hangzhou。*/
const char *region = "yourRegion";
void init_options(oss_request_options_t *options)
{
    options->config = oss_config_create(options->pool);
    /* 用char*類型的字串初始化aos_string_t類型。*/
    aos_str_set(&options->config->endpoint, endpoint);
    /* 從環境變數中擷取訪問憑證。運行本程式碼範例之前,請確保已設定環境變數OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。*/    
    aos_str_set(&options->config->access_key_id, getenv("OSS_ACCESS_KEY_ID"));
    aos_str_set(&options->config->access_key_secret, getenv("OSS_ACCESS_KEY_SECRET"));
    //需要額外配置以下兩個參數
    aos_str_set(&options->config->region, region);
    options->config->signature_version = 4;
    /* 是否使用了CNAME。0表示不使用。*/
    options->config->is_cname = 0;
    /* 設定網路相關參數,比如逾時時間等。*/
    options->ctl = aos_http_controller_create(options->pool, 0);
}
int main(int argc, char *argv[])
{
    aos_pool_t *p = NULL;
    aos_status_t *s = NULL;
    aos_string_t bucket;
    aos_string_t object;
    aos_table_t *headers = NULL;
    oss_request_options_t *options = NULL;
    aos_table_t *resp_headers = NULL;
    aos_list_t resp_body;
    aos_list_t buffer;
    aos_buf_t *content;
    char *buf = NULL;
    int64_t len = 0;
    int64_t size = 0;
    int64_t pos = 0;
    char b64_buf[1024];
    int b64_len;
    /* 採用JSON格式。*/
    /*(可選)設定回調請求訊息頭中Host的值,如您的伺服器配置Host的值。*/
    char *callback =  "{"
        "\"callbackUrl\":\"http://oss-demo.aliyuncs.com:23450\","
         "\"callbackHost\":\"yourCallbackHost\","
        "\"callbackBody\":\"bucket=${bucket}&object=${object}&size=${size}&mimeType=${mimeType}\","
        "\"callbackBodyType\":\"application/x-www-form-urlencoded\""
        "}";
    /* 在程式入口調用aos_http_io_initialize方法來初始化網路、記憶體等全域資源。*/
    if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
        exit(1);
    }
    /* 初始化參數。*/
    aos_pool_create(&p, NULL);
    options = oss_request_options_create(p);
    init_options(options);
    aos_str_set(&bucket, bucket_name);
    aos_str_set(&object, object_name);
    aos_list_init(&resp_body);
    aos_list_init(&buffer);
    content = aos_buf_pack(options->pool, object_content, strlen(object_content));
    aos_list_add_tail(&content->node, &buffer);
    /* 將callback放入header。*/
    b64_len = aos_base64_encode((unsigned char*)callback, strlen(callback), b64_buf);
    b64_buf[b64_len] = '\0';
    headers = aos_table_make(p, 1);
    apr_table_set(headers, OSS_CALLBACK, b64_buf);
    /* 上傳回調。*/
    s = oss_do_put_object_from_buffer(options, &bucket, &object, &buffer,
        headers, NULL, NULL, &resp_headers, &resp_body);
    if (aos_status_is_ok(s)) {
        printf("put object from buffer succeeded\n");
    } else {
        printf("put object from buffer failed\n");
    }
    /* 擷取buffer長度。*/
    len = aos_buf_list_len(&resp_body);
    buf = (char *)aos_pcalloc(p, (apr_size_t)(len + 1));
    buf[len] = '\0';
    /* 拷貝buffer內容到記憶體。*/
    aos_list_for_each_entry(aos_buf_t, content, &resp_body, node) {
        size = aos_buf_size(content);
        memcpy(buf + pos, content->pos, (size_t)size);
        pos += size;
    }
    /* 釋放記憶體池,相當於釋放了請求過程中各資源分派的記憶體。*/
    aos_pool_destroy(p);
    /* 釋放之前分配的全域資源。*/
    aos_http_io_deinitialize();
    return 0;
}

相關文檔

  • 關於上傳回調的完整範例程式碼,請參見GitHub樣本

  • 關於上傳回調的API介面說明,請參見Callback