test_util.cc

/* Copyright 2021 The ChromiumOS Authors
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "test_util.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "util.h"

#define MAX_PIPE_CAPACITY (4096)

FILE* write_to_pipe(const std::string& content) {
  int pipefd[2];
  if (pipe(pipefd) == -1) {
    die("pipe(pipefd) failed");
  }

  size_t len = content.length();
  if (len > MAX_PIPE_CAPACITY)
    die("write_to_pipe cannot handle >4KB content.");
  size_t i = 0;
  unsigned int attempts = 0;
  ssize_t ret;
  while (i < len) {
    ret = write(pipefd[1], content.c_str() + i, len - i);
    if (ret == -1) {
      close(pipefd[0]);
      close(pipefd[1]);
      return NULL;
    }

    /* If we write 0 bytes three times in a row, fail. */
    if (ret == 0) {
      if (++attempts >= 3) {
        close(pipefd[0]);
        close(pipefd[1]);
        warn("write() returned 0 three times in a row");
        return NULL;
      }
      continue;
    }

    attempts = 0;
    i += (size_t)ret;
  }

  close(pipefd[1]);
  return fdopen(pipefd[0], "r");
}

std::string source_path(const std::string& file) {
  std::string srcdir = getenv("SRC") ?: ".";
  return srcdir + "/" + file;
}