C
C
Get Object MetaData from Google Cloud Storage
See more Google Cloud Storage Examples
Demonstrates how to download a Google Cloud Storage object's metadata.Chilkat C Downloads
#include <C_CkStringBuilder.h>
#include <C_CkHttp.h>
void ChilkatSample(void)
{
BOOL success;
HCkStringBuilder sbToken;
HCkHttp http;
const char *url;
HCkStringBuilder sbMetaData;
int responseCode;
success = FALSE;
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
// This example uses a previously obtained access token having permission for the
// scope "https://www.googleapis.com/auth/cloud-platform"
// In this example, Get Google Cloud Storage OAuth2 Access Token,
// the service account access token was saved to a text file. This example fetches the access token from the file..
sbToken = CkStringBuilder_Create();
CkStringBuilder_LoadFile(sbToken,"qa_data/tokens/googleCloudStorageAccessToken.txt","utf-8");
// Send a GET equivalent to this curl command.
// curl -X GET \
// -H "Authorization: Bearer [OAUTH2_TOKEN]" \
// -o "[SAVE_TO_LOCATION]" \
// "https://www.googleapis.com/storage/v1/b/[BUCKET_NAME]/o/[OBJECT_NAME]?projection=full"
http = CkHttp_Create();
CkHttp_putAuthToken(http,CkStringBuilder_getAsString(sbToken));
// Construct a URL to download the metadata for the object named "starfish.jpg" located in the "chilkat-ocean" bucket.
CkHttp_SetUrlVar(http,"bucket_name","chilkat-ocean");
CkHttp_SetUrlVar(http,"object_name","starfish.jpg");
url = "https://www.googleapis.com/storage/v1/b/{$bucket_name}/o/{$object_name}?projection=full";
// If there is an error response, then we didn't actually download the metadata,
// but instead we downloaded an error response..
sbMetaData = CkStringBuilder_Create();
success = CkHttp_DownloadSb(http,url,"utf-8",sbMetaData);
if (success == FALSE) {
printf("%s\n",CkHttp_lastErrorText(http));
CkStringBuilder_Dispose(sbToken);
CkHttp_Dispose(http);
CkStringBuilder_Dispose(sbMetaData);
return;
}
responseCode = CkHttp_getLastStatus(http);
if (responseCode == 401) {
printf("If invalid credentials, then it is likely the access token expired.\n");
printf("Your app should automatically fetch a new access token and re-try.\n");
}
if (responseCode != 200) {
printf("Error response code = %d\n",responseCode);
printf("Error:\n");
printf("%s\n",CkStringBuilder_getAsString(sbMetaData));
CkStringBuilder_Dispose(sbToken);
CkHttp_Dispose(http);
CkStringBuilder_Dispose(sbMetaData);
return;
}
printf("%s\n",CkStringBuilder_getAsString(sbMetaData));
printf("Success.\n");
// Sample output:
// {
// "kind": "storage#object",
// "id": "chilkat-ocean/starfish.jpg/1502670320090292",
// "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg",
// "name": "starfish.jpg",
// "bucket": "chilkat-ocean",
// "generation": "1502670320090292",
// "metageneration": "1",
// "contentType": "image/jpeg",
// "timeCreated": "2017-08-14T00:25:20.040Z",
// "updated": "2017-08-14T00:25:20.040Z",
// "storageClass": "MULTI_REGIONAL",
// "timeStorageClassUpdated": "2017-08-14T00:25:20.040Z",
// "size": "6229",
// "md5Hash": "LpxZ2/JmI2fcl9/dqF2gSA==",
// "mediaLink": "https://www.googleapis.com/download/storage/v1/b/chilkat-ocean/o/starfish.jpg?generation=1502670320090292&alt=media",
// "acl": [
// {
// "kind": "storage#objectAccessControl",
// "id": "chilkat-ocean/starfish.jpg/1502670320090292/project-owners-933037264567",
// "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/project-owners-933037264567",
// "bucket": "chilkat-ocean",
// "object": "starfish.jpg",
// "generation": "1502670320090292",
// "entity": "project-owners-933037264567",
// "role": "OWNER",
// "projectTeam": {
// "projectNumber": "933037264567",
// "team": "owners"
// },
// "etag": "CLT5kpW71dUCEAE="
// },
// {
// "kind": "storage#objectAccessControl",
// "id": "chilkat-ocean/starfish.jpg/1502670320090292/project-editors-933037264567",
// "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/project-editors-933037264567",
// "bucket": "chilkat-ocean",
// "object": "starfish.jpg",
// "generation": "1502670320090292",
// "entity": "project-editors-933037264567",
// "role": "OWNER",
// "projectTeam": {
// "projectNumber": "933037264567",
// "team": "editors"
// },
// "etag": "CLT5kpW71dUCEAE="
// },
// {
// "kind": "storage#objectAccessControl",
// "id": "chilkat-ocean/starfish.jpg/1502670320090292/project-viewers-933037264567",
// "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/project-viewers-933037264567",
// "bucket": "chilkat-ocean",
// "object": "starfish.jpg",
// "generation": "1502670320090292",
// "entity": "project-viewers-933037264567",
// "role": "READER",
// "projectTeam": {
// "projectNumber": "933037264567",
// "team": "viewers"
// },
// "etag": "CLT5kpW71dUCEAE="
// },
// {
// "kind": "storage#objectAccessControl",
// "id": "chilkat-ocean/starfish.jpg/1502670320090292/user-starfish@chilkat-176611.iam.gserviceaccount.com",
// "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg/acl/user-starfish@chilkat-176611.iam.gserviceaccount.com",
// "bucket": "chilkat-ocean",
// "object": "starfish.jpg",
// "generation": "1502670320090292",
// "entity": "user-starfish@chilkat-176611.iam.gserviceaccount.com",
// "role": "OWNER",
// "email": "starfish@chilkat-176611.iam.gserviceaccount.com",
// "etag": "CLT5kpW71dUCEAE="
// }
// ],
// "owner": {
// "entity": "user-starfish@chilkat-176611.iam.gserviceaccount.com"
// },
// "crc32c": "9RjgwQ==",
// "etag": "CLT5kpW71dUCEAE="
// }
//
CkStringBuilder_Dispose(sbToken);
CkHttp_Dispose(http);
CkStringBuilder_Dispose(sbMetaData);
}