/* This file is part of limb                           https://lila.oss/limb
 * Copyright (C) 2023 Olivier Brunel                          jjk@jjacky.com */
/* SPDX-License-Identifier: GPL-2.0-only */
#include <errno.h>
#include <limb/buffer-shldata.h>
#include <limb/shldata.h>
#include <limb/siovec.h>
#include "buffer-shldata.h"

int
buffer_shldata_getfull(buffer *b, shldata_getfull fn, void *args,
                       stralloc *sa, buffer_shldata_ctx *ctx)
{
    struct iovec v[2];
    ssize_t o;
    size_t salen, l;

    salen = sa->len;
    for(;;) {
        buffer_rpeek(b, v);
        /* make sure we can put the whole buffer into our sa */
        if (!stralloc_readyplus(sa, siov_len(v, 2)))
            return (sa->len = salen, 0);
        /* and gather it */
        l = siov_gather(sa->s + sa->len, sa->a - sa->len, v, 2);
        /* try the getfull fn() */
        o = fn(sa->s + salen, sa->len - salen + l, args, ctx);
        /* in case of ENODATA we "appropriate" the buffer's content & refill */
        if (o < 0 && errno == ENODATA) {
            sa->len += l;
            buffer_rseek(b, l);
            o = buffer_fill(b);
            if (o > 0)
                continue;
        }
        break;
    }
    if (o <= 0) {
        sa->len = salen;
        return (!o) ? (errno = EPIPE, 0) : 0;
    }

    buffer_rseek(b, o - (sa->len - salen));
    sa->len = salen;
    return 1;
}