hdfs_read.c
上传用户:quxuerui
上传日期:2018-01-08
资源大小:41811k
文件大小:2k
- /**
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements. See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership. The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- #include "hdfs.h"
- int main(int argc, char **argv) {
- if (argc != 4) {
- fprintf(stderr, "Usage: hdfs_read <filename> <filesize> <buffersize>n");
- exit(-1);
- }
-
- hdfsFS fs = hdfsConnect("default", 0);
- if (!fs) {
- fprintf(stderr, "Oops! Failed to connect to hdfs!n");
- exit(-1);
- }
-
- const char* rfile = argv[1];
- tSize fileTotalSize = strtoul(argv[2], NULL, 10);
- tSize bufferSize = strtoul(argv[3], NULL, 10);
-
- hdfsFile readFile = hdfsOpenFile(fs, rfile, O_RDONLY, bufferSize, 0, 0);
- if (!readFile) {
- fprintf(stderr, "Failed to open %s for writing!n", rfile);
- exit(-2);
- }
- // data to be written to the file
- char* buffer = malloc(sizeof(char) * bufferSize);
- if(buffer == NULL) {
- return -2;
- }
-
- // read from the file
- tSize curSize = bufferSize;
- for (; curSize == bufferSize;) {
- curSize = hdfsRead(fs, readFile, (void*)buffer, curSize);
- }
-
- free(buffer);
- hdfsCloseFile(fs, readFile);
- hdfsDisconnect(fs);
- return 0;
- }
- /**
- * vim: ts=4: sw=4: et:
- */