htop/pcp/PCPMetric.c

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/*
htop - PCPMetric.c
(C) 2020-2021 htop dev team
(C) 2020-2021 Red Hat, Inc.
Released under the GNU GPLv2+, see the COPYING file
in the source distribution for its full text.
*/
#include "config.h" // IWYU pragma: keep
#include "pcp/PCPMetric.h"
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include "XUtils.h"
#include "pcp/Platform.h"
extern Platform* pcp;
const pmDesc* PCPMetric_desc(PCPMetric metric) {
return &pcp->descs[metric];
}
int PCPMetric_type(PCPMetric metric) {
return pcp->descs[metric].type;
}
pmAtomValue* PCPMetric_values(PCPMetric metric, pmAtomValue* atom, int count, int type) {
if (pcp->result == NULL)
return NULL;
pmValueSet* vset = pcp->result->vset[metric];
if (!vset || vset->numval <= 0)
return NULL;
/* extract requested number of values as requested type */
const pmDesc* desc = &pcp->descs[metric];
for (int i = 0; i < vset->numval; i++) {
if (i == count)
break;
const pmValue* value = &vset->vlist[i];
int sts = pmExtractValue(vset->valfmt, value, desc->type, &atom[i], type);
if (sts < 0) {
if (pmDebugOptions.appl0)
fprintf(stderr, "Error: cannot extract metric value: %s\n",
pmErrStr(sts));
memset(&atom[i], 0, sizeof(pmAtomValue));
}
}
return atom;
}
int PCPMetric_instanceCount(PCPMetric metric) {
pmValueSet* vset = pcp->result->vset[metric];
if (vset)
return vset->numval;
return 0;
}
int PCPMetric_instanceOffset(PCPMetric metric, int inst) {
pmValueSet* vset = pcp->result->vset[metric];
if (!vset || vset->numval <= 0)
return 0;
/* search for optimal offset for subsequent inst lookups to begin */
for (int i = 0; i < vset->numval; i++) {
if (inst == vset->vlist[i].inst)
return i;
}
return 0;
}
static pmAtomValue* PCPMetric_extract(PCPMetric metric, int inst, int offset, pmValueSet* vset, pmAtomValue* atom, int type) {
/* extract value (using requested type) of given metric instance */
const pmDesc* desc = &pcp->descs[metric];
const pmValue* value = &vset->vlist[offset];
int sts = pmExtractValue(vset->valfmt, value, desc->type, atom, type);
if (sts < 0) {
if (pmDebugOptions.appl0)
fprintf(stderr, "Error: cannot extract %s instance %d value: %s\n",
pcp->names[metric], inst, pmErrStr(sts));
memset(atom, 0, sizeof(pmAtomValue));
}
return atom;
}
pmAtomValue* PCPMetric_instance(PCPMetric metric, int inst, int offset, pmAtomValue* atom, int type) {
pmValueSet* vset = pcp->result->vset[metric];
if (!vset || vset->numval <= 0)
return NULL;
/* fast-path using heuristic offset based on expected location */
if (offset >= 0 && offset < vset->numval && inst == vset->vlist[offset].inst)
return PCPMetric_extract(metric, inst, offset, vset, atom, type);
/* slow-path using a linear search for the requested instance */
for (int i = 0; i < vset->numval; i++) {
if (inst == vset->vlist[i].inst)
return PCPMetric_extract(metric, inst, i, vset, atom, type);
}
return NULL;
}
/*
* Iterate over a set of instances (incl PM_IN_NULL)
* returning the next instance identifier and offset.
*
* Start it off by passing offset -1 into the routine.
*/
bool PCPMetric_iterate(PCPMetric metric, int* instp, int* offsetp) {
if (!pcp->result)
return false;
pmValueSet* vset = pcp->result->vset[metric];
if (!vset || vset->numval <= 0)
return false;
int offset = *offsetp;
offset = (offset < 0) ? 0 : offset + 1;
if (offset > vset->numval - 1)
return false;
*offsetp = offset;
*instp = vset->vlist[offset].inst;
return true;
}
/* Switch on/off a metric for value fetching (sampling) */
void PCPMetric_enable(PCPMetric metric, bool enable) {
pcp->fetch[metric] = enable ? pcp->pmids[metric] : PM_ID_NULL;
}
bool PCPMetric_enabled(PCPMetric metric) {
return pcp->fetch[metric] != PM_ID_NULL;
}
void PCPMetric_enableThreads(void) {
pmValueSet* vset = xCalloc(1, sizeof(pmValueSet));
vset->vlist[0].inst = PM_IN_NULL;
vset->vlist[0].value.lval = 1;
vset->valfmt = PM_VAL_INSITU;
vset->numval = 1;
vset->pmid = pcp->pmids[PCP_CONTROL_THREADS];
pmResult* result = xCalloc(1, sizeof(pmResult));
result->vset[0] = vset;
result->numpmid = 1;
int sts = pmStore(result);
if (sts < 0 && pmDebugOptions.appl0)
fprintf(stderr, "Error: cannot enable threads: %s\n", pmErrStr(sts));
pmFreeResult(result);
}
bool PCPMetric_fetch(struct timeval* timestamp) {
if (pcp->result) {
pmFreeResult(pcp->result);
pcp->result = NULL;
}
int sts = pmFetch(pcp->totalMetrics, pcp->fetch, &pcp->result);
if (sts < 0) {
if (pmDebugOptions.appl0)
fprintf(stderr, "Error: cannot fetch metric values: %s\n",
pmErrStr(sts));
return false;
}
if (timestamp)
*timestamp = pcp->result->timestamp;
return true;
}