Scippy

SCIP

Solving Constraint Integer Programs

reader_mst.c
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1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2 /* */
3 /* This file is part of the program and library */
4 /* SCIP --- Solving Constraint Integer Programs */
5 /* */
6 /* Copyright 2002-2022 Zuse Institute Berlin */
7 /* */
8 /* Licensed under the Apache License, Version 2.0 (the "License"); */
9 /* you may not use this file except in compliance with the License. */
10 /* You may obtain a copy of the License at */
11 /* */
12 /* http://www.apache.org/licenses/LICENSE-2.0 */
13 /* */
14 /* Unless required by applicable law or agreed to in writing, software */
15 /* distributed under the License is distributed on an "AS IS" BASIS, */
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17 /* See the License for the specific language governing permissions and */
18 /* limitations under the License. */
19 /* */
20 /* You should have received a copy of the Apache-2.0 license */
21 /* along with SCIP; see the file LICENSE. If not visit scipopt.org. */
22 /* */
23 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
24 
25 /**@file reader_mst.c
26  * @ingroup DEFPLUGINS_READER
27  * @brief file reader for partial primal solutions (like MIP-start of Cplex)
28  * @author Jakob Witzig
29  *
30  */
31 
32 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
33 
34 #include <ctype.h>
35 #include "scip/pub_fileio.h"
36 #include "scip/pub_message.h"
37 #include "scip/pub_misc.h"
38 #include "scip/pub_reader.h"
39 #include "scip/reader_mst.h"
40 #include "scip/scip_general.h"
41 #include "scip/scip_message.h"
42 #include "scip/scip_param.h"
43 #include "scip/scip_reader.h"
44 #include "scip/scip_sol.h"
45 #include <string.h>
46 
47 #define READER_NAME "mstreader"
48 #define READER_DESC "file reader for partial primal solutions"
49 #define READER_EXTENSION "mst"
50 
51 
52 /*
53  * Local methods of reader
54  */
55 
56 /** reads a given SCIP solution file, problem has to be transformed in advance */
57 static
59  SCIP* scip, /**< SCIP data structure */
60  const char* fname, /**< name of the input file */
61  SCIP_Bool xml /**< true, iff the given file is XML */
62  )
63 {
64  SCIP_SOL* sol;
65  SCIP_Bool error;
66  SCIP_Bool stored;
67  SCIP_Bool usevartable;
68 
69  assert(scip != NULL);
70  assert(fname != NULL);
71 
72  SCIP_CALL( SCIPgetBoolParam(scip, "misc/usevartable", &usevartable) );
73 
74  if( !usevartable )
75  {
76  SCIPerrorMessage("Cannot read solution file if vartable is disabled. Make sure parameter 'misc/usevartable' is set to TRUE.\n");
77  return SCIP_READERROR;
78  }
79 
80  /* create zero solution */
81  SCIP_CALL( SCIPcreatePartialSol(scip, &sol, NULL) );
82 
83  SCIP_CALL( SCIPreadSolFile(scip, fname, sol, xml, NULL, &error) );
84 
85  if( !error )
86  {
87  assert(!SCIPisTransformed(scip));
88 
89  /* add primal solution to solution candidate storage, frees the solution afterwards */
90  SCIP_CALL( SCIPaddSolFree(scip, &sol, &stored) );
91 
92  /* display result */
93  SCIPverbMessage(scip, SCIP_VERBLEVEL_NORMAL, NULL, "partial primal solution from solution file <%s> was accepted as candidate, will be completed and checked when solving starts\n",
94  fname);
95 
96  return SCIP_OKAY;
97  }
98  else
99  {
100  /* free solution */
101  SCIP_CALL( SCIPfreeSol(scip, &sol) );
102 
103  return SCIP_READERROR;
104  }
105 }
106 
107 /*
108  * Callback methods of reader
109  */
110 
111 /** copy method for reader plugins (called when SCIP copies plugins) */
112 static
113 SCIP_DECL_READERCOPY(readerCopyMst)
114 { /*lint --e{715}*/
115  assert(scip != NULL);
116  assert(reader != NULL);
117  assert(strcmp(SCIPreaderGetName(reader), READER_NAME) == 0);
118 
119  /* call inclusion method of reader */
121 
122  return SCIP_OKAY;
123 }
124 
125 
126 /** problem reading method of reader
127  *
128  * In order to determine the type of the file, we have to open it. Thus, it has to be opened
129  * twice. This might be removed, but is likely to not hurt the performance too much.
130  */
131 static
132 SCIP_DECL_READERREAD(readerReadMst)
133 { /*lint --e{715}*/
134  SCIP_FILE* file;
135  char buffer[SCIP_MAXSTRLEN];
136 
137  assert(reader != NULL);
138  assert(strcmp(SCIPreaderGetName(reader), READER_NAME) == 0);
139  assert(result != NULL);
140 
141  *result = SCIP_DIDNOTRUN;
142 
144  {
145  SCIPerrorMessage("reading of partial solution file is only possible after a problem was created\n");
146  return SCIP_READERROR;
147  }
148 
150  {
151  SCIPerrorMessage("reading of partial solution file is only possible before the solving process is started\n");
152  return SCIP_READERROR;
153  }
154 
155  /* open input file in order to determine type */
156  file = SCIPfopen(filename, "r");
157  if( file == NULL )
158  {
159  SCIPerrorMessage("cannot open file <%s> for reading\n", filename);
160  SCIPprintSysError(filename);
161  return SCIP_NOFILE;
162  }
163 
164  /* get next line */
165  if( SCIPfgets(buffer, (int) sizeof(buffer), file) == NULL )
166  {
167  SCIPerrorMessage("cannot parse file.\n");
168  SCIPfclose(file);
169  return SCIP_READERROR;
170  }
171  /* close file */
172  SCIPfclose(file);
173 
174  /* decide whether it is xml */
175  if( SCIPstrAtStart(buffer, "<?xml", (size_t) 5) )
176  {
177  /* read XML solution and add it to the solution pool */
178  SCIP_CALL( readMst(scip, filename, TRUE) );
179  }
180  else
181  {
182  /* read the solution and add it to the solution pool */
183  SCIP_CALL( readMst(scip, filename, FALSE) );
184  }
185 
186  *result = SCIP_SUCCESS;
187 
188  return SCIP_OKAY;
189 }
190 
191 
192 /*
193  * sol file reader specific interface methods
194  */
195 
196 /** includes the mst file reader in SCIP */
198  SCIP* scip /**< SCIP data structure */
199  )
200 {
201  SCIP_READER* reader;
202 
203  /* include reader */
205 
206  assert(reader != NULL);
207 
208  /* set non fundamental callbacks via setter functions */
209  SCIP_CALL( SCIPsetReaderCopy(scip, reader, readerCopyMst) );
210  SCIP_CALL( SCIPsetReaderRead(scip, reader, readerReadMst) );
211 
212  return SCIP_OKAY;
213 }
SCIP_RETCODE SCIPcreatePartialSol(SCIP *scip, SCIP_SOL **sol, SCIP_HEUR *heur)
Definition: scip_sol.c:505
public methods for SCIP parameter handling
SCIP_STAGE SCIPgetStage(SCIP *scip)
Definition: scip_general.c:365
#define READER_NAME
Definition: reader_mst.c:47
#define SCIP_MAXSTRLEN
Definition: def.h:302
SCIP_RETCODE SCIPaddSolFree(SCIP *scip, SCIP_SOL **sol, SCIP_Bool *stored)
Definition: scip_sol.c:3024
const char * SCIPreaderGetName(SCIP_READER *reader)
Definition: reader.c:557
#define FALSE
Definition: def.h:96
#define TRUE
Definition: def.h:95
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
static SCIP_RETCODE readMst(SCIP *scip, const char *fname, SCIP_Bool xml)
Definition: reader_mst.c:58
SCIP_Bool SCIPisTransformed(SCIP *scip)
Definition: scip_general.c:575
SCIP_FILE * SCIPfopen(const char *path, const char *mode)
Definition: fileio.c:153
#define READER_EXTENSION
Definition: reader_mst.c:49
SCIP_Bool SCIPstrAtStart(const char *s, const char *t, size_t tlen)
Definition: misc.c:11274
#define SCIPerrorMessage
Definition: pub_message.h:64
struct SCIP_File SCIP_FILE
Definition: pub_fileio.h:43
char * SCIPfgets(char *s, int size, SCIP_FILE *stream)
Definition: fileio.c:200
SCIP_RETCODE SCIPincludeReaderMst(SCIP *scip)
Definition: reader_mst.c:197
SCIP_RETCODE SCIPgetBoolParam(SCIP *scip, const char *name, SCIP_Bool *value)
Definition: scip_param.c:250
#define NULL
Definition: lpi_spx1.cpp:164
#define SCIP_CALL(x)
Definition: def.h:393
void SCIPverbMessage(SCIP *scip, SCIP_VERBLEVEL msgverblevel, FILE *file, const char *formatstr,...)
Definition: scip_message.c:225
wrapper functions to map file i/o to standard or zlib file i/o
public data structures and miscellaneous methods
#define SCIP_Bool
Definition: def.h:93
SCIP_RETCODE SCIPincludeReaderBasic(SCIP *scip, SCIP_READER **readerptr, const char *name, const char *desc, const char *extension, SCIP_READERDATA *readerdata)
Definition: scip_reader.c:109
void SCIPprintSysError(const char *message)
Definition: misc.c:10673
SCIP_RETCODE SCIPfreeSol(SCIP *scip, SCIP_SOL **sol)
Definition: scip_sol.c:985
SCIP_RETCODE SCIPsetReaderCopy(SCIP *scip, SCIP_READER *reader, SCIP_DECL_READERCOPY((*readercopy)))
Definition: scip_reader.c:147
static SCIP_DECL_READERCOPY(readerCopyMst)
Definition: reader_mst.c:113
general public methods
SCIP_RETCODE SCIPreadSolFile(SCIP *scip, const char *filename, SCIP_SOL *sol, SCIP_Bool xml, SCIP_Bool *partial, SCIP_Bool *error)
Definition: scip_sol.c:2894
public methods for solutions
public methods for message output
public methods for input file readers
public methods for message handling
SCIP_RETCODE SCIPsetReaderRead(SCIP *scip, SCIP_READER *reader, SCIP_DECL_READERREAD((*readerread)))
Definition: scip_reader.c:195
file reader for partial primal solutions
int SCIPfclose(SCIP_FILE *fp)
Definition: fileio.c:232
#define READER_DESC
Definition: reader_mst.c:48
public methods for reader plugins
static SCIP_DECL_READERREAD(readerReadMst)
Definition: reader_mst.c:132