/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ This program is free software; you can redistribute it and/or modify         │
│ it under the terms of the GNU General Public License as published by         │
│ the Free Software Foundation; version 2 of the License.                      │
│                                                                              │
│ This program is distributed in the hope that it will be useful, but          │
│ WITHOUT ANY WARRANTY; without even the implied warranty of                   │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU             │
│ General Public License for more details.                                     │
│                                                                              │
│ You should have received a copy of the GNU General Public License            │
│ along with this program; if not, write to the Free Software                  │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
│ 02110-1301 USA                                                               │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/bits/safemacros.h"
#include "libc/calls/calls.h"
#include "libc/calls/struct/stat.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/runtime/gc.h"
#include "libc/runtime/runtime.h"
#include "libc/stdio/stdio.h"
#include "libc/testlib/testlib.h"
#include "libc/x/x.h"

int rc;
struct stat st;
const char *path;
int64_t fd, emptyspace, physicalspace;

TEST(fallocate_000, setup) {
  mkdir("o", 0755);
  mkdir("o/tmp", 0755);
}

TEST(fallocate_010, testBadFileDescriptor) {
  if (IsFreebsd()) return; /* TODO: FreeBSD failing to set carry flag bug */
  ASSERT_EQ(-1, fallocate(/*RHEL*/ 5, 0, 0, 1));
  if (errno == ENOSYS) exit(0);
  EXPECT_EQ(EBADF, errno);
}

TEST(fallocate_020, test) {
  path = gc(xasprintf("o/tmp/%s.%d", program_invocation_short_name));
  ASSERT_NE(-1, (fd = creat(path, 0755)));
  ASSERT_EQ(5, write(fd, "hello", 5));
  errno = 31337;
  ASSERT_NE(-1, fallocate(fd, 0, 0, 31337));
  EXPECT_EQ(31337, errno);
  ASSERT_EQ(5, write(fd, "world", 5));
  ASSERT_NE(-1, close(fd));
  ASSERT_NE(-1, stat(path, &st));
  ASSERT_EQ(31337, st.st_size);
  ASSERT_BINEQ(u"helloworld", gc(xslurp(path, NULL)));
  unlink(path);
}

TEST(fallocate_020, testSparseFile) {
  ASSERT_NE(-1, stat("o", &st));
  emptyspace = rounddown(6 * 1000 * 1000 * 1000, st.st_blksize);
  physicalspace = roundup(4096, st.st_blksize);
  path = gc(xasprintf("o/tmp/%s.%d", program_invocation_short_name, getpid()));
  ASSERT_NE(-1, (fd = creat(path, 0755)));
  rc = fallocate(fd, 0, emptyspace, physicalspace);
  if (rc == -1) {
    /*
     * most important feature is failing w/ enosys if not possible to
     * allocate storage like a central banker prints money.
     */
    ASSERT_EQ(ENOSYS, errno);
  }
  ASSERT_EQ(emptyspace, lseek(fd, emptyspace, SEEK_SET));
  ASSERT_EQ(5, write(fd, "hello", 5));
  ASSERT_NE(-1, fsync(fd));
  ASSERT_NE(-1, close(fd));
  ASSERT_NE(-1, stat(path, &st));
  EXPECT_EQ(emptyspace + physicalspace, st.st_size);
  /*
   * don't care how much physical space system needs, so long as it's
   * transparent and less than 10 percent the fake space
   */
  EXPECT_NE(0, st.st_blocks);
  EXPECT_LT(st.st_blocks * 512, emptyspace / 10);
  unlink(path);
}