GRASS GIS 8 Programmer's Manual 8.4.1(2025)-45ca3179ab
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ami_stream.cpp
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1/****************************************************************************
2 *
3 * MODULE: iostream
4 *
5
6 * COPYRIGHT (C) 2007 Laura Toma
7 *
8 *
9
10 * Iostream is a library that implements streams, external memory
11 * sorting on streams, and an external memory priority queue on
12 * streams. These are the fundamental components used in external
13 * memory algorithms.
14
15 * Credits: The library was developed by Laura Toma. The kernel of
16 * class STREAM is based on the similar class existent in the GPL TPIE
17 * project developed at Duke University. The sorting and priority
18 * queue have been developed by Laura Toma based on communications
19 * with Rajiv Wickremesinghe. The library was developed as part of
20 * porting Terraflow to GRASS in 2001. PEARL upgrades in 2003 by
21 * Rajiv Wickremesinghe as part of the Terracost project.
22
23 *
24 * This program is free software; you can redistribute it and/or modify
25 * it under the terms of the GNU General Public License as published by
26 * the Free Software Foundation; either version 2 of the License, or
27 * (at your option) any later version.
28 *
29
30 * This program is distributed in the hope that it will be useful,
31 * but WITHOUT ANY WARRANTY; without even the implied warranty of
32 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
33 * General Public License for more details. *
34 * **************************************************************************/
35
36#include <sys/types.h>
37#include <sys/stat.h>
38#include <stdio.h>
39#include <stdlib.h>
40#include <assert.h>
41#include <fcntl.h>
42#include <errno.h>
43#include <unistd.h>
44
45extern "C" {
46#include <grass/gis.h>
47}
48
49// #include <ami_stream.h>
50#include <grass/iostream/ami_stream.h>
51
52const char *ami_str_error[] = {
53 "AMI_ERROR_NO_ERROR",
54 "AMI_ERROR_IO_ERROR",
55 "AMI_ERROR_END_OF_STREAM",
56 "AMI_ERROR_OUT_OF_RANGE",
57 "AMI_ERROR_READ_ONLY",
58 "AMI_ERROR_OS_ERROR",
59 "AMI_ERROR_MM_ERROR",
60 "AMI_ERROR_OBJECT_INITIALIZATION",
61 "AMI_ERROR_PERMISSION_DENIED",
62 "AMI_ERROR_INSUFFICIENT_MAIN_MEMORY",
63 "AMI_ERROR_INSUFFICIENT_AVAILABLE_STREAMS",
64 "AMI_ERROR_ENV_UNDEFINED",
65 "AMI_ERROR_NO_MAIN_MEMORY_OPERATION",
66};
67
68/**********************************************************************/
69/* creates a random file name, opens the file for reading and writing
70 and and returns a file descriptor */
71int ami_single_temp_name(const std::string &base, char *tmp_path)
72{
73
74 char *base_dir;
75 int fd;
76
77 // get the dir
78 base_dir = getenv(STREAM_TMPDIR);
79 if (!base_dir) {
80 fprintf(stderr, "ami_stream: %s not set\n", STREAM_TMPDIR);
81 assert(base_dir);
82 exit(1);
83 }
84 snprintf(tmp_path, GPATH_MAX, "%s/%s_XXXXXX", base_dir, base.c_str());
85
86 fd = G_mkstemp(tmp_path, O_RDWR, 0600);
87
88 if (fd == -1) {
89 cerr << "ami_single_temp_name: ";
90 perror("G_mkstemp() failed: ");
91 assert(0);
92 exit(1);
93 }
94 return fd;
95}
96
97/**********************************************************************/
98/* given fd=fide descriptor, associates with it a stream aopened in
99 access_mode and returns it */
100FILE *open_stream(int fd, AMI_stream_type st)
101{
102 FILE *fp = NULL;
103
104 assert(fd > -1);
105 switch (st) {
106 case AMI_READ_STREAM:
107 fp = fdopen(fd, "rb");
108 break;
109 case AMI_WRITE_STREAM:
110 fp = fdopen(fd, "wb");
111 break;
112 case AMI_APPEND_WRITE_STREAM:
113 fp = fdopen(fd, "ab");
114 break;
115 case AMI_APPEND_STREAM:
116 fp = fdopen(fd, "ab+");
117 break;
118 case AMI_READ_WRITE_STREAM:
119 fp = fdopen(fd, "rb+");
120 if (!fp) {
121 // if file does not exist, create it
122 fp = fdopen(fd, "wb+");
123 }
124 break;
125 }
126 if (!fp) {
127 perror("fdopen");
128 }
129 assert(fp);
130
131 return fp;
132}
133
134/**********************************************************************/
135/* open the file whose name is pathname in access mode */
136FILE *open_stream(char *pathname, AMI_stream_type st)
137{
138
139 FILE *fp = NULL;
140 assert(pathname);
141
142 switch (st) {
143 case AMI_READ_STREAM:
144 fp = fopen(pathname, "rb");
145 break;
146 case AMI_WRITE_STREAM:
147 fp = fopen(pathname, "wb");
148 break;
149 case AMI_APPEND_WRITE_STREAM:
150 fp = fopen(pathname, "ab");
151 break;
152 case AMI_APPEND_STREAM:
153 fp = fopen(pathname, "ab+");
154 assert(fp);
155 G_fseek(fp, 0, SEEK_END);
156 break;
157 case AMI_READ_WRITE_STREAM:
158 fp = fopen(pathname, "rb+");
159 if (!fp) {
160 // if file does not exist, create it
161 fp = fopen(pathname, "wb+");
162 }
163 break;
164 }
165 if (!fp) {
166 perror(pathname);
167 assert(0);
168 exit(1);
169 }
170 assert(fp);
171 return fp;
172}
FILE * open_stream(int fd, AMI_stream_type st)
const char * ami_str_error[]
int ami_single_temp_name(const std::string &base, char *tmp_path)
#define NULL
Definition ccmath.h:32
void G_fseek(FILE *fp, off_t offset, int whence)
Change the file position of the stream.
Definition gis/seek.c:50
#define assert(condition)
Definition lz4.c:393
int G_mkstemp(char *template, int flags, int mode)
Returns a file descriptor.
Definition mkstemp.c:128