Method writeKV_impl

fdbclient/FileBackupAgent.actor.cpp:652–678

	// Start a new block if needed, then write the key and value
	ACTOR static Future<Void> writeKV_impl(LogFileWriter* self, Key k, Value v) {
		// If key and value do not fit in this block, end it and start a new one
		int toWrite = sizeof(int32_t) + k.size() + sizeof(int32_t) + v.size();
		if (self->file->size() + toWrite > self->blockEnd) {
			// Write padding if needed
			int bytesLeft = self->blockEnd - self->file->size();
			if (bytesLeft > 0) {
				state Value paddingFFs = makePadding(bytesLeft);
				wait(self->file->append(paddingFFs.begin(), bytesLeft));
			}

			// Set new blockEnd
			self->blockEnd += self->blockSize;

			// write the block header
			wait(self->file->append((uint8_t*)&BACKUP_AGENT_MLOG_VERSION, sizeof(BACKUP_AGENT_MLOG_VERSION)));
		}

		wait(self->file->appendStringRefWithLen(k));
		wait(self->file->appendStringRefWithLen(v));

		// At this point we should be in whatever the current block is or the block size is too small
		if (self->file->size() > self->blockEnd)
			throw backup_bad_block_size();

		return Void();
	}

	Future<Void> writeKV(Key k, Value v) { return writeKV_impl(this, k, v); }