ingraphs.c

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/*************************************************************************
 * Copyright (c) 2011 AT&T Intellectual Property 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors: Details at https://graphviz.org
 *************************************************************************/
 
 
/*
 * Written by Emden Gansner
 */
 
#include <cgraph/cgraph.h>
#include <cgraph/ingraphs.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
 
 
/* Set next available file.
 * If Files is NULL, we just read from stdin.
 */
static void nextFile(ingraph_state * sp)
{
    void *rv = NULL;
    char *fname;
 
    if (sp->u.Files == NULL) {
        if (sp->ctr++ == 0) {
            rv = stdin;
        }
    } else {
        while ((fname = sp->u.Files[sp->ctr++])) {
            if (*fname == '-') {
                rv = stdin;
                break;
            } else if ((rv = fopen(fname, "r")) != 0)
                break;
            else {
                fprintf(stderr, "Can't open %s\n", sp->u.Files[sp->ctr - 1]);
                sp->errors++;
            }
        }
    }
    if (rv)
        agsetfile(fileName(sp));
    sp->fp = rv;
}
 
/* Read and return next graph; return NULL if done.
 * Read graph from currently open file. If none, open next file.
 */
Agraph_t *nextGraph(ingraph_state * sp)
{
    Agraph_t *g;
 
    if (sp->ingraphs) {
        g = sp->u.Graphs[sp->ctr];
        if (g) sp->ctr++;
        return g;
    }
    if (sp->fp == NULL)
        nextFile(sp);
    g = NULL;
 
    while (sp->fp != NULL) {
        if ((g = sp->readf(sp->fp)) != 0)
            break;
        if (sp->u.Files)        /* Only close if not using stdin */
            (void)fclose(sp->fp);
        nextFile(sp);
    }
    return g;
}
 
/* Create new ingraph state. If sp is non-NULL, we
 * assume user is supplying memory.
 */
static ingraph_state*
new_ing(ingraph_state * sp, char **files, Agraph_t** graphs, Agraph_t *(*readf)(void*))
{
    if (!sp) {
        sp = malloc(sizeof(ingraph_state));
        if (!sp) {
            fprintf(stderr, "ingraphs: out of memory\n");
            return 0;
        }
        sp->heap = true;
    } else
        sp->heap = false;
    if (graphs) {
        sp->ingraphs = 1;
        sp->u.Graphs = graphs;
    }
    else {
        sp->ingraphs = 0;
        sp->u.Files = files;
    }
    sp->ctr = 0;
    sp->errors = 0;
    sp->fp = NULL;
    if (!readf) {
        if (sp->heap)
            free(sp);
        fprintf(stderr, "ingraphs: NULL read function\n");
        return 0;
    }
    sp->readf = readf;
    return sp;
}
 
ingraph_state *newIng(ingraph_state *sp, char **files,
                      Agraph_t *(*readf)(void *)) {
  return new_ing(sp, files, 0, readf);
}
 
/* Create new ingraph state using supplied graphs. If sp is non-NULL, we
 * assume user is supplying memory.
 */
ingraph_state *newIngGraphs(ingraph_state *sp, Agraph_t **graphs,
                            Agraph_t *(*readf)(void *)) {
  return new_ing(sp, 0, graphs, readf);
}
 
static Agraph_t *dflt_read(void *fp) {
  return agread(fp, NULL);
}
 
/* At present, we require opf to be non-NULL. In
 * theory, we could assume a function agread(FILE*,void*)
 */
ingraph_state *newIngraph(ingraph_state * sp, char **files) {
  return newIng(sp, files, dflt_read);
}
 
/* Close any open files and free discipline
 * Free sp if necessary.
 */
void closeIngraph(ingraph_state * sp)
{
    if (!sp->ingraphs && sp->u.Files && sp->fp)
        (void)fclose(sp->fp);
    if (sp->heap)
        free(sp);
}
 
char *fileName(ingraph_state * sp)
{
    char *fname;
 
    if (sp->ingraphs) {
        return "<>";
    }
    else if (sp->u.Files) {
        if (sp->ctr) {
            fname = sp->u.Files[sp->ctr - 1];
            if (*fname == '-')
                return "<stdin>";
            else
                return fname;
        } else
            return "<>";
    } else
        return "<stdin>";
}