// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2014, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
 */
#include "array.h"
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

void fdarray__init(struct fdarray *fda, int nr_autogrow)
{
        fda->entries     = NULL;
        fda->priv        = NULL;
        fda->nr          = fda->nr_alloc = 0;
        fda->nr_autogrow = nr_autogrow;
}

int fdarray__grow(struct fdarray *fda, int nr)
{
        struct priv *priv;
        int nr_alloc = fda->nr_alloc + nr;
        size_t psize = sizeof(fda->priv[0]) * nr_alloc;
        size_t size  = sizeof(struct pollfd) * nr_alloc;
        struct pollfd *entries = realloc(fda->entries, size);

        if (entries == NULL)
                return -ENOMEM;

        priv = realloc(fda->priv, psize);
        if (priv == NULL) {
                free(entries);
                return -ENOMEM;
        }

        memset(&entries[fda->nr_alloc], 0, sizeof(struct pollfd) * nr);
        memset(&priv[fda->nr_alloc], 0, sizeof(fda->priv[0]) * nr);

        fda->nr_alloc = nr_alloc;
        fda->entries  = entries;
        fda->priv     = priv;
        return 0;
}

struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow)
{
        struct fdarray *fda = calloc(1, sizeof(*fda));

        if (fda != NULL) {
                if (fdarray__grow(fda, nr_alloc)) {
                        free(fda);
                        fda = NULL;
                } else {
                        fda->nr_autogrow = nr_autogrow;
                }
        }

        return fda;
}

void fdarray__exit(struct fdarray *fda)
{
        free(fda->entries);
        free(fda->priv);
        fdarray__init(fda, 0);
}

void fdarray__delete(struct fdarray *fda)
{
        fdarray__exit(fda);
        free(fda);
}

int fdarray__add(struct fdarray *fda, int fd, short revents, enum fdarray_flags flags)
{
        int pos = fda->nr;

        if (fda->nr == fda->nr_alloc &&
            fdarray__grow(fda, fda->nr_autogrow) < 0)
                return -ENOMEM;

        fda->entries[fda->nr].fd     = fd;
        fda->entries[fda->nr].events = revents;
        fda->priv[fda->nr].flags = flags;
        fda->nr++;
        return pos;
}

int fdarray__dup_entry_from(struct fdarray *fda, int pos, struct fdarray *from)
{
        struct pollfd *entry;
        int npos;

        if (pos >= from->nr)
                return -EINVAL;

        entry = &from->entries[pos];

        npos = fdarray__add(fda, entry->fd, entry->events, from->priv[pos].flags);
        if (npos >= 0)
                fda->priv[npos] = from->priv[pos];

        return npos;
}

int fdarray__filter(struct fdarray *fda, short revents,
                    void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
                    void *arg)
{
        int fd, nr = 0;

        if (fda->nr == 0)
                return 0;

        for (fd = 0; fd < fda->nr; ++fd) {
                if (!fda->entries[fd].events)
                        continue;

                if (fda->entries[fd].revents & revents) {
                        if (entry_destructor)
                                entry_destructor(fda, fd, arg);

                        fda->entries[fd].revents = fda->entries[fd].events = 0;
                        continue;
                }

                if (!(fda->priv[fd].flags & fdarray_flag__nonfilterable))
                        ++nr;
        }

        return nr;
}

int fdarray__poll(struct fdarray *fda, int timeout)
{
        return poll(fda->entries, fda->nr, timeout);
}

int fdarray__fprintf(struct fdarray *fda, FILE *fp)
{
        int fd, printed = fprintf(fp, "%d [ ", fda->nr);

        for (fd = 0; fd < fda->nr; ++fd)
                printed += fprintf(fp, "%s%d", fd ? ", " : "", fda->entries[fd].fd);

        return printed + fprintf(fp, " ]");
}