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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* Copyright (C) 2019, Google Inc.
*
* utils.cpp - Miscellaneous utility functions
*/
#include "utils.h"
#include <dlfcn.h>
#include <elf.h>
#include <iomanip>
#include <link.h>
#include <sstream>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
/**
* \file utils.h
* \brief Miscellaneous utility functions
*/
/* musl doesn't declare _DYNAMIC in link.h, declare it manually. */
extern ElfW(Dyn) _DYNAMIC[];
namespace libcamera {
namespace utils {
/**
* \def ARRAY_SIZE(array)
* \brief Determine the number of elements in the static array.
*/
/**
* \brief Strip the directory prefix from the path
* \param[in] path The path to process
*
* basename is implemented differently across different C libraries. This
* implementation matches the one provided by the GNU libc, and does not
* modify its input parameter.
*
* \return A pointer within the given path without any leading directory
* components.
*/
const char *basename(const char *path)
{
const char *base = strrchr(path, '/');
return base ? base + 1 : path;
}
/**
* \brief Get an environment variable
* \param[in] name The name of the variable to return
*
* The environment list is searched to find the variable 'name', and the
* corresponding string is returned.
*
* If 'secure execution' is required then this function always returns NULL to
* avoid vulnerabilities that could occur if set-user-ID or set-group-ID
* programs accidentally trust the environment.
*
* \return A pointer to the value in the environment or NULL if the requested
* environment variable doesn't exist or if secure execution is required.
*/
char *secure_getenv(const char *name)
{
#if HAVE_SECURE_GETENV
return ::secure_getenv(name);
#else
if (issetugid())
return NULL;
return getenv(name);
#endif
}
/**
* \brief Identify the dirname portion of a path
* \param[in] path The full path to parse
*
* This function conforms with the behaviour of the %dirname() function as
* defined by POSIX.
*
* \return A string of the directory component of the path
*/
std::string dirname(const std::string &path)
{
if (path.empty())
return ".";
/*
* Skip all trailing slashes. If the path is only made of slashes,
* return "/".
*/
size_t pos = path.size() - 1;
while (path[pos] == '/') {
if (!pos)
return "/";
pos--;
}
/*
* Find the previous slash. If the path contains no non-trailing slash,
* return ".".
*/
while (path[pos] != '/') {
if (!pos)
return ".";
pos--;
}
/*
* Return the directory name up to (but not including) any trailing
* slash. If this would result in an empty string, return "/".
*/
while (path[pos] == '/') {
if (!pos)
return "/";
pos--;
}
return path.substr(0, pos + 1);
}
/**
* \fn libcamera::utils::set_overlap(InputIt1 first1, InputIt1 last1,
* InputIt2 first2, InputIt2 last2)
* \brief Count the number of elements in the intersection of two ranges
*
* Count the number of elements in the intersection of the sorted ranges [\a
* first1, \a last1) and [\a first1, \a last2). Elements are compared using
* operator< and the ranges must be sorted with respect to the same.
*
* \return The number of elements in the intersection of the two ranges
*/
/**
* \fn libcamera::utils::clamp(const T& v, const T& lo, const T& hi)
* \param[in] v The value to clamp
* \param[in] lo The lower boundary to clamp v to
* \param[in] hi The higher boundary to clamp v to
* \return lo if v is less than lo, hi if v is greater than hi, otherwise v
*/
/**
* \typedef clock
* \brief The libcamera clock (monotonic)
*/
/**
* \typedef duration
* \brief The libcamera duration related to libcamera::utils::clock
*/
/**
* \typedef time_point
* \brief The libcamera time point related to libcamera::utils::clock
*/
/**
* \brief Convert a duration to a timespec
* \param[in] value The duration
* \return A timespec expressing the duration
*/
struct timespec duration_to_timespec(const duration &value)
{
uint64_t nsecs = std::chrono::duration_cast<std::chrono::nanoseconds>(value).count();
struct timespec ts;
ts.tv_sec = nsecs / 1000000000ULL;
ts.tv_nsec = nsecs % 1000000000ULL;
return ts;
}
/**
* \brief Convert a time point to a string representation
* \param[in] time The time point
* \return A string representing the time point in hh:mm:ss.nanoseconds format
*/
std::string time_point_to_string(const time_point &time)
{
uint64_t nsecs = std::chrono::duration_cast<std::chrono::nanoseconds>(time.time_since_epoch()).count();
unsigned int secs = nsecs / 1000000000ULL;
std::ostringstream ossTimestamp;
ossTimestamp.fill('0');
ossTimestamp << secs / (60 * 60) << ":"
<< std::setw(2) << (secs / 60) % 60 << ":"
<< std::setw(2) << secs % 60 << "."
<< std::setw(9) << nsecs % 1000000000ULL;
return ossTimestamp.str();
}
std::basic_ostream<char, std::char_traits<char>> &
operator<<(std::basic_ostream<char, std::char_traits<char>> &stream, const _hex &h)
{
stream << "0x";
std::ostream::fmtflags flags = stream.setf(std::ios_base::hex,
std::ios_base::basefield);
std::streamsize width = stream.width(h.w);
char fill = stream.fill('0');
stream << h.v;
stream.flags(flags);
stream.width(width);
stream.fill(fill);
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