Backup describe, expire, and delete will now clearly indicate when there is no backup at the given URL.

fdbbackup/backup.actor.cpp

@@ -1901,12 +1901,11 @@ ACTOR Future<Void> deleteBackupContainer(const char *name, std::string destinati
 		state Future<Void> done = c->deleteContainer(&numDeleted);
 
 		state int lastUpdate = -1;
-		printf("Deleting data...\n");
+		printf("Deleting %s...\n", destinationContainer.c_str());
 
 		loop {
 			choose {
 				when ( Void _ = wait(done) ) {
-					printf("The entire container has been deleted.\n");
 					break;
 				}
 				when ( Void _ = wait(delay(5)) ) {
@@ -1918,6 +1917,7 @@ ACTOR Future<Void> deleteBackupContainer(const char *name, std::string destinati
 			}
 		}
 		printf("\r%d objects deleted\n", numDeleted);
+		printf("The entire container has been deleted.\n");
 	}
 	catch (Error& e) {
 		if(e.code() == error_code_actor_cancelled)

fdbclient/BackupContainer.actor.cpp

@@ -200,6 +200,7 @@ public:
 
 	// Create the container
 	virtual Future<Void> create() = 0;
+	virtual Future<bool> exists() = 0;
 
 	// Get a list of fileNames and their sizes in the container under the given path
 	// Although not required, an implementation can avoid traversing unwanted subfolders
@@ -550,6 +551,12 @@ public:
 			.detail("URL", bc->getURL())
 			.detail("LogStartVersionOverride", logStartVersionOverride);
 
+		bool e = wait(bc->exists());
+		if(!e) {
+			TraceEvent(SevWarnAlways, "BackupContainerDoesNotExist").detail("URL", bc->getURL());
+			throw backup_does_not_exist();
+		}
+
 		// If logStartVersion is relative, then first do a recursive call without it to find the max log version
 		// from which to resolve the relative version.
 		// This could be handled more efficiently without recursion but it's tricky, this will do for now.
@@ -1115,6 +1122,11 @@ public:
 		return Void();
 	}
 
+	// The container exists if the folder it resides in exists
+	Future<bool> exists() {
+		return directoryExists(m_path);
+	}
+
 	Future<Reference<IAsyncFile>> readFile(std::string path) {
 		int flags = IAsyncFile::OPEN_NO_AIO | IAsyncFile::OPEN_READONLY | IAsyncFile::OPEN_UNCACHED;
 		// Simulation does not properly handle opening the same file from multiple machines using a shared filesystem,
@@ -1361,7 +1373,18 @@ public:
 		return create_impl(Reference<BackupContainerBlobStore>::addRef(this));
 	}
 
+	// The container exists if the index entry in the blob bucket exists
+	Future<bool> exists() {
+		return m_bstore->objectExists(m_bucket, indexEntry());
+	}
+
 	ACTOR static Future<Void> deleteContainer_impl(Reference<BackupContainerBlobStore> bc, int *pNumDeleted) {
+		bool e = wait(bc->exists());
+		if(!e) {
+			TraceEvent(SevWarnAlways, "BackupContainerDoesNotExist").detail("URL", bc->getURL());
+			throw backup_does_not_exist();
+		}
+
 		// First delete everything under the data prefix in the bucket
 		Void _ = wait(bc->m_bstore->deleteRecursively(bc->m_bucket, bc->dataPath(""), pNumDeleted));
 

fdbclient/BackupContainer.h

@@ -162,6 +162,7 @@ public:
 
 	// Create the container
 	virtual Future<Void> create() = 0;
+	virtual Future<bool> exists() = 0;
 
 	// Open a log file or range file for writing
 	virtual Future<Reference<IBackupFile>> writeLogFile(Version beginVersion, Version endVersion, int blockSize) = 0;

flow/Platform.cpp

@@ -2062,6 +2062,19 @@ bool fileExists(std::string const& filename) {
 	return true;
 }
 
+bool directoryExists(std::string const& path) {
+#ifdef _WIN32
+	DWORD bits = ::GetFileAttributes(path.c_str());
+	return bits != INVALID_FILE_ATTRIBUTES && (bits & FILE_ATTRIBUTE_DIRECTORY);
+#else
+	DIR *d = opendir(path.c_str());
+	if(d == nullptr)
+		return false;
+	closedir(d);
+	return true;
+#endif
+}
+
 int64_t fileSize(std::string const& filename) {
 #ifdef _WIN32
 	struct _stati64 file_status;

flow/Platform.h

@@ -285,6 +285,9 @@ void threadYield();  // Attempt to yield to other processes or threads
 // Returns true iff the file exists
 bool fileExists(std::string const& filename);
 
+// Returns true iff the directory exists
+bool directoryExists(std::string const& path);
+
 // Returns size of file in bytes
 int64_t fileSize(std::string const& filename);
 

flow/error_definitions.h

@@ -177,6 +177,7 @@ ERROR( backup_invalid_info, 2315, "Backup Container URL invalid")
 ERROR( backup_cannot_expire, 2316, "Cannot expire requested data from backup without violating minimum restorability")
 ERROR( backup_auth_missing, 2317, "Cannot find authentication details (such as a password or secret key) for the specified Backup Container URL")
 ERROR( backup_auth_unreadable, 2318, "Cannot read or parse one or more sources of authentication information for Backup Container URLs")
+ERROR( backup_does_not_exist, 2319, "Backup does not exist")
 ERROR( restore_invalid_version, 2361, "Invalid restore version")
 ERROR( restore_corrupted_data, 2362, "Corrupted backup data")
 ERROR( restore_missing_data, 2363, "Missing backup data")