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libuv/src/win/util.c  view on Meta::CPAN

#include <direct.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <wchar.h>

#include "uv.h"
#include "internal.h"

#include <winsock2.h>
#include <winperf.h>
#include <iphlpapi.h>
#include <psapi.h>
#include <tlhelp32.h>
#include <windows.h>
#include <userenv.h>
#include <math.h>

/*
 * Max title length; the only thing MSDN tells us about the maximum length
 * of the console title is that it is smaller than 64K. However in practice
 * it is much smaller, and there is no way to figure out what the exact length
 * of the title is or can be, at least not on XP. To make it even more
 * annoying, GetConsoleTitle fails when the buffer to be read into is bigger
 * than the actual maximum length. So we make a conservative guess here;
 * just don't put the novel you're writing in the title, unless the plot
 * survives truncation.
 */
#define MAX_TITLE_LENGTH 8192

/* The number of nanoseconds in one second. */
#define UV__NANOSEC 1000000000

/* Max user name length, from iphlpapi.h */
#ifndef UNLEN
# define UNLEN 256
#endif


/* Maximum environment variable size, including the terminating null */
#define MAX_ENV_VAR_LENGTH 32767

/* Cached copy of the process title, plus a mutex guarding it. */
static char *process_title;
static CRITICAL_SECTION process_title_lock;

/* Interval (in seconds) of the high-resolution clock. */
static double hrtime_interval_ = 0;


/*
 * One-time initialization code for functionality defined in util.c.
 */
void uv__util_init(void) {
  LARGE_INTEGER perf_frequency;

  /* Initialize process title access mutex. */
  InitializeCriticalSection(&process_title_lock);

  /* Retrieve high-resolution timer frequency
   * and precompute its reciprocal.
   */
  if (QueryPerformanceFrequency(&perf_frequency)) {
    hrtime_interval_ = 1.0 / perf_frequency.QuadPart;
  } else {
    hrtime_interval_= 0;
  }
}


int uv_exepath(char* buffer, size_t* size_ptr) {
  int utf8_len, utf16_buffer_len, utf16_len;
  WCHAR* utf16_buffer;
  int err;

  if (buffer == NULL || size_ptr == NULL || *size_ptr == 0) {
    return UV_EINVAL;
  }

  if (*size_ptr > 32768) {
    /* Windows paths can never be longer than this. */
    utf16_buffer_len = 32768;
  } else {
    utf16_buffer_len = (int) *size_ptr;
  }

  utf16_buffer = (WCHAR*) uv__malloc(sizeof(WCHAR) * utf16_buffer_len);
  if (!utf16_buffer) {
    return UV_ENOMEM;
  }

  /* Get the path as UTF-16. */
  utf16_len = GetModuleFileNameW(NULL, utf16_buffer, utf16_buffer_len);
  if (utf16_len <= 0) {
    err = GetLastError();
    goto error;
  }

  /* utf16_len contains the length, *not* including the terminating null. */
  utf16_buffer[utf16_len] = L'\0';

  /* Convert to UTF-8 */
  utf8_len = WideCharToMultiByte(CP_UTF8,
                                 0,
                                 utf16_buffer,
                                 -1,
                                 buffer,
                                 (int) *size_ptr,
                                 NULL,
                                 NULL);
  if (utf8_len == 0) {
    err = GetLastError();
    goto error;
  }

  uv__free(utf16_buffer);

  /* utf8_len *does* include the terminating null at this point, but the
   * returned size shouldn't. */
  *size_ptr = utf8_len - 1;