htop/FileDescriptorMeter.c

119 lines
3.6 KiB
C

/*
htop - FileDescriptorMeter.c
(C) 2022 htop dev team
Released under the GNU GPLv2+, see the COPYING file
in the source distribution for its full text.
*/
#include "config.h" // IWYU pragma: keep
#include "FileDescriptorMeter.h"
#include <math.h>
#include "CRT.h"
#include "Macros.h"
#include "Meter.h"
#include "Object.h"
#include "Platform.h"
#include "RichString.h"
#include "XUtils.h"
#define FD_EFFECTIVE_UNLIMITED(x) (!isgreaterequal((double)(1<<30), (x)))
static const int FileDescriptorMeter_attributes[] = {
FILE_DESCRIPTOR_USED,
FILE_DESCRIPTOR_MAX
};
static void FileDescriptorMeter_updateValues(Meter* this) {
this->values[0] = 0;
this->values[1] = 1;
Platform_getFileDescriptors(&this->values[0], &this->values[1]);
/* only print bar for first value */
this->curItems = 1;
/* Use maximum value for scaling of bar mode
*
* As the plain total value can be very large compared to
* the actually used value, this is capped in the following way:
*
* 1. If the maximum value is below (or equal to) 1<<16, use it directly
* 2. If the maximum value is above, use powers of 2 starting at 1<<16 and
* double it until it's larger than 16 times the used file handles
* (capped at the maximum number of files)
* 3. If the maximum is effectively unlimited (AKA > 1<<30),
* Do the same as for 2, but cap at 1<<30.
*/
if (this->values[1] <= 1 << 16) {
this->total = this->values[1];
} else {
if (this->total < 16 * this->values[0]) {
for (this->total = 1 << 16; this->total < 16 * this->values[0]; this->total *= 2) {
if (this->total >= 1 << 30) {
break;
}
}
}
if (this->total > this->values[1]) {
this->total = this->values[1];
}
if (this->total > 1 << 30) {
this->total = 1 << 30;
}
}
if (!isNonnegative(this->values[0])) {
xSnprintf(this->txtBuffer, sizeof(this->txtBuffer), "unknown/unknown");
} else if (FD_EFFECTIVE_UNLIMITED(this->values[1])) {
xSnprintf(this->txtBuffer, sizeof(this->txtBuffer), "%.0lf/unlimited", this->values[0]);
} else {
xSnprintf(this->txtBuffer, sizeof(this->txtBuffer), "%.0lf/%.0lf", this->values[0], this->values[1]);
}
}
static void FileDescriptorMeter_display(const Object* cast, RichString* out) {
const Meter* this = (const Meter*)cast;
char buffer[50];
int len;
if (!isNonnegative(this->values[0])) {
RichString_appendAscii(out, CRT_colors[METER_TEXT], "unknown");
return;
}
RichString_appendAscii(out, CRT_colors[METER_TEXT], "used: ");
len = xSnprintf(buffer, sizeof(buffer), "%.0lf", this->values[0]);
RichString_appendnAscii(out, CRT_colors[FILE_DESCRIPTOR_USED], buffer, len);
RichString_appendAscii(out, CRT_colors[METER_TEXT], " max: ");
if (FD_EFFECTIVE_UNLIMITED(this->values[1])) {
RichString_appendAscii(out, CRT_colors[FILE_DESCRIPTOR_MAX], "unlimited");
} else {
len = xSnprintf(buffer, sizeof(buffer), "%.0lf", this->values[1]);
RichString_appendnAscii(out, CRT_colors[FILE_DESCRIPTOR_MAX], buffer, len);
}
}
const MeterClass FileDescriptorMeter_class = {
.super = {
.extends = Class(Meter),
.delete = Meter_delete,
.display = FileDescriptorMeter_display,
},
.updateValues = FileDescriptorMeter_updateValues,
.defaultMode = TEXT_METERMODE,
.maxItems = 2,
.total = 65536.0,
.attributes = FileDescriptorMeter_attributes,
.name = "FileDescriptors",
.uiName = "File Descriptors",
.caption = "FDs: ",
.description = "Number of allocated/available file descriptors"
};