用于读取read文件和创建线程进行写入read的函数

Author: ErianArcher

read_io.cpp

@@ -0,0 +1,98 @@
+//
+// Created by 梁俊鹏 on 2019-07-20.
+//
+
+#include <iostream>
+#include <stdio.h>
+#include <string.h>
+#include "read_io.h"
+#include "entity/read.h"
+
+#define BUFFER_SIZE 152
+
+using namespace std;
+
+//block_queue<string> *ioqueue = new block_queue<string>;
+
+static int thisRank;
+static int host_num;
+static string path;
+static string *fnames;
+static int fileAmount = 0;
+static int curIndex4Fnames;
+static fpos_t curSeek;
+static char buffer[BUFFER_SIZE];
+static FILE *infile;
+
+int moveToNext() {
+    fclose(infile);
+    curSeek = 0ll;
+    if (curIndex4Fnames + 1 >= fileAmount) {
+        cout << "All files are read." << endl;
+        return 0;
+    }
+    string fname = path + fnames[++curIndex4Fnames];
+    infile = fopen(fname.c_str(), "r");
+    if (!infile) {
+        cerr << "Unable to open file: " << fname << endl;
+        return -1;
+    }
+    return 1;
+}
+
+int readIOInit(int currank, int world_size, string filepath, string *filenames, int fileNum) {
+    thisRank = currank;
+    host_num = world_size;
+    path = filepath;
+    fnames = filenames;
+    fileAmount = fileNum;
+    curIndex4Fnames = -1; // 因为moveToNext需要直接增加
+    curSeek = 0ll;
+    if (nullptr == filenames) {
+        cerr << "No input read file." << endl;
+        return -1;
+    }
+    while (moveToNext() == -1);
+    if (curIndex4Fnames + 1 >= fileAmount) return -1;
+    return 0;
+}
+
+int getNextRead(string *outread, size_t *readpos) {
+    if (fileAmount < 1) return -1;
+    // 先尝试读取，如果不能读取则转向下一个文件
+    while (fgets(buffer, BUFFER_SIZE, infile) == NULL) {
+        int flag;
+        while ((flag = moveToNext()) == -1) ; // 当读到的文件不能打开则马上打开下一个
+        if (flag == 0) return -1; // 全部读完则返回-1
+    }
+    *readpos = curSeek; // 读取前的位置
+    fgetpos(infile, &curSeek);
+
+    int len = strlen(buffer) - 1;
+    *outread = string(buffer, len);
+
+    return 1;
+}
+
+string getCurrentFilename() {
+    return fnames[curIndex4Fnames];
+}
+
+pthread_t requestWriteRead(const string &read) {
+    pthread_t tid;
+    if (pthread_create(&tid, NULL, writeReadRunner, (void *)&read) == -1) {
+        cerr << "Error: Cannot create thread when requesting read writing." << endl;
+        return 0;
+    }
+    pthread_detach(tid);
+    return tid;
+}
+
+void *writeReadRunner(void *arg) {
+    string read = *((string *) arg);
+    if (createRead(read, nullptr) == 0) {
+        cerr << "Error: Cannot create file for read \"" << read << "\"" << endl;
+        return (void *) -1;
+    }
+    return (void *)0;
+}

read_io.h

@@ -0,0 +1,23 @@
+//
+// Created by 梁俊鹏 on 2019-07-20.
+//
+
+#ifndef RANDOMSTRINGASSEMBLY_READ_IO_H
+#define RANDOMSTRINGASSEMBLY_READ_IO_H
+
+#include <pthread.h>
+#include <string>
+
+using namespace std;
+
+int readIOInit(int currank, int world_size, string filepath, string *filenames, int fileNum);
+
+int getNextRead(string *outread, size_t *readpos);
+
+string getCurrentFilename();
+
+pthread_t requestWriteRead(const string &read);
+
+void *writeReadRunner(void *arg);
+
+#endif //RANDOMSTRINGASSEMBLY_READ_IO_H