msharee9 commented on a change in pull request #590: MINIFICPP-621 Nanofi Tailfile example URL: https://github.com/apache/nifi-minifi-cpp/pull/590#discussion_r293198638
########## File path: nanofi/examples/tail_file.c ########## @@ -0,0 +1,270 @@ +/* + * 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 "api/nanofi.h" +#include <unistd.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <errno.h> +#include <limits.h> +#include <sys/stat.h> + +typedef struct flow_file_records { + flow_file_record ** records; + uint64_t len; +} flow_file_records; + +typedef struct file_offset { + int offset; +} file_offset; + +struct flow_file_records * flowfiles = NULL; +struct file_offset * fileoffset = NULL; +struct nifi_instance * instance = NULL; + +void transmit_flow_files(nifi_instance * instance) { + if (flowfiles) { + for (int i = 0; i < flowfiles->len; ++i) { + if (flowfiles->records[i]) { + transmit_flowfile(flowfiles->records[i], instance); + } + } + } +} + +char * get_string(char * begin, char * end) { + + if (begin == NULL || (end != NULL && end < begin)) { + return NULL; + } + + int len = 0; + char * buff = NULL; + + if (begin == end) { + buff = (char *)malloc(2 * sizeof(char)); + strncpy(buff, begin, 1); + buff[1] = '\0'; + return buff; + } + + if (end) { + len = end - begin; + buff = (char *)malloc((len+1) * sizeof(char)); + strncpy(buff, begin, len); + buff[len] = '\0'; + } + else { + len = strlen(begin); + buff = (char *)malloc((len+1) * sizeof(char)); + strncpy(buff, begin, len); + buff[len] = '\0'; + } + return buff; +} + +void split_string(char * str, char delim, char ** collector, int * num_strings) +{ + if (!str) return; + + while (*str == delim) str++; + + char * p = strchr(str, delim); + if (p) { + char * s = get_string(str, p); + if (s == NULL) { + return; + } + collector[*num_strings] = s; + (*num_strings)++; + split_string(p+1, delim, collector, num_strings); + } + else { + char * s = get_string(str, NULL); + if (s == NULL) { + return; + } + collector[*num_strings] = s; + (*num_strings)++; + } +} + +void set_offset(int offset) { + fileoffset->offset = offset; +} + +int get_offset() { + return fileoffset->offset; +} + +void free_all_strings(char ** strings, int num_strings) { + for (int i = 0; i < num_strings; ++i) { + if (strings[i]) free(strings[i]); + } +} + +void on_trigger_callback(processor_session * ps, processor_context * ctx) { + + char file_path[50]; + char delimiter[2]; + + if (get_property(ctx, "file_path", file_path, 50) != 0) { + return; + } + + if (get_property(ctx, "delimiter", delimiter, 2) != 0) { + return; + } + + char delim = '\0'; + if (strlen(delimiter) > 0) { + delim = delimiter[0]; + } + + if (delim == '\0') { + printf("Invalid delimiter \n"); + return; + } + + if (delim == '\\') { + if (strlen(delimiter) > 1) { + switch (delimiter[1]) { + case 'r': + delim = '\r'; + break; + case 't': + delim = '\t'; + break; + case 'n': + delim = '\n'; + break; + case '\\': + delim = '\\'; + break; + default: + break; + } + } + } + + int curr_offset = get_offset(); + int max_bytes_read = 4096; + char buff[max_bytes_read]; + FILE * fp = fopen(file_path, "rb"); + if (!fp) return; + fseek(fp, curr_offset, SEEK_SET); + while (fgets(buff, max_bytes_read, fp) != NULL) { Review comment: Changed the implementation. Now using fread. Please see the updated code. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
