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/* SPDX-License-Identifier: GPL-3.0-or-later */
#include "config.h"
#include "libnetdata/libnetdata.h"
void netdata_cleanup_and_exit(int ret) {
exit(ret);
}
#define PF_PREFIX "PROCFILE"
#define PFWORDS_INCREASE_STEP 200
#define PFLINES_INCREASE_STEP 10
#define PROCFILE_INCREMENT_BUFFER 512
extern size_t procfile_max_lines;
extern size_t procfile_max_words;
extern size_t procfile_max_allocation;
static inline void pflines_reset(pflines *fl) {
// debug(D_PROCFILE, PF_PREFIX ": reseting lines");
fl->len = 0;
}
static inline void pflines_free(pflines *fl) {
// debug(D_PROCFILE, PF_PREFIX ": freeing lines");
freez(fl);
}
static inline void pfwords_reset(pfwords *fw) {
// debug(D_PROCFILE, PF_PREFIX ": reseting words");
fw->len = 0;
}
static inline void pfwords_add(procfile *ff, char *str) {
// debug(D_PROCFILE, PF_PREFIX ": adding word No %d: '%s'", fw->len, str);
pfwords *fw = ff->words;
if(unlikely(fw->len == fw->size)) {
// debug(D_PROCFILE, PF_PREFIX ": expanding words");
ff->words = fw = reallocz(fw, sizeof(pfwords) + (fw->size + PFWORDS_INCREASE_STEP) * sizeof(char *));
fw->size += PFWORDS_INCREASE_STEP;
}
fw->words[fw->len++] = str;
}
NEVERNULL
static inline size_t *pflines_add(procfile *ff) {
// debug(D_PROCFILE, PF_PREFIX ": adding line %d at word %d", fl->len, first_word);
pflines *fl = ff->lines;
if(unlikely(fl->len == fl->size)) {
// debug(D_PROCFILE, PF_PREFIX ": expanding lines");
ff->lines = fl = reallocz(fl, sizeof(pflines) + (fl->size + PFLINES_INCREASE_STEP) * sizeof(ffline));
fl->size += PFLINES_INCREASE_STEP;
}
ffline *ffl = &fl->lines[fl->len++];
ffl->words = 0;
ffl->first = ff->words->len;
return &ffl->words;
}
NOINLINE
static void procfile_parser(procfile *ff) {
// debug(D_PROCFILE, PF_PREFIX ": Parsing file '%s'", ff->filename);
char *s = ff->data // our current position
, *e = &ff->data[ff->len] // the terminating null
, *t = ff->data; // the first character of a word (or quoted / parenthesized string)
// the look up array to find our type of character
PF_CHAR_TYPE *separators = ff->separators;
char quote = 0; // the quote character - only when in quoted string
size_t opened = 0; // counts the number of open parenthesis
size_t *line_words = pflines_add(ff);
while(s < e) {
PF_CHAR_TYPE ct = separators[(unsigned char)(*s)];
// this is faster than a switch()
// read more here: http://lazarenko.me/switch/
switch(ct) {
case PF_CHAR_IS_SEPARATOR:
if(!quote && !opened) {
if (s != t) {
// separator, but we have word before it
*s = '\0';
pfwords_add(ff, t);
(*line_words)++;
}
t = s + 1;
}
// fallthrough
case PF_CHAR_IS_WORD:
s++;
break;
case PF_CHAR_IS_NEWLINE:
// end of line
*s = '\0';
pfwords_add(ff, t);
(*line_words)++;
t = ++s;
// debug(D_PROCFILE, PF_PREFIX ": ended line %d with %d words", l, ff->lines->lines[l].words);
line_words = pflines_add(ff);
break;
case PF_CHAR_IS_QUOTE:
if(unlikely(!quote && s == t)) {
// quote opened at the beginning
quote = *s;
t = ++s;
}
else if(unlikely(quote && quote == *s)) {
// quote closed
quote = 0;
*s = '\0';
pfwords_add(ff, t);
(*line_words)++;
t = ++s;
}
else
s++;
break;
case PF_CHAR_IS_OPEN:
if(s == t) {
opened++;
t = ++s;
}
else if(opened) {
opened++;
s++;
}
else
s++;
break;
case PF_CHAR_IS_CLOSE:
if(opened) {
opened--;
if(!opened) {
*s = '\0';
pfwords_add(ff, t);
(*line_words)++;
t = ++s;
}
else
s++;
}
else
s++;
break;
default:
fatal("Internal Error: procfile_readall() does not handle all the cases.");
}
}
if(likely(s > t && t < e)) {
// the last word
if(unlikely(ff->len >= ff->size)) {
// we are going to loose the last byte
s = &ff->data[ff->size - 1];
}
*s = '\0';
pfwords_add(ff, t);
(*line_words)++;
// t = ++s;
}
}
procfile *procfile_readall1(procfile *ff) {
// debug(D_PROCFILE, PF_PREFIX ": Reading file '%s'.", ff->filename);
ff->len = 0; // zero the used size
ssize_t r = 1; // read at least once
while(r > 0) {
ssize_t s = ff->len;
ssize_t x = ff->size - s;
if(unlikely(!x)) {
debug(D_PROCFILE, PF_PREFIX ": Expanding data buffer for file '%s'.", procfile_filename(ff));
ff = reallocz(ff, sizeof(procfile) + ff->size + PROCFILE_INCREMENT_BUFFER);
ff->size += PROCFILE_INCREMENT_BUFFER;
}
debug(D_PROCFILE, "Reading file '%s', from position %zd with length %zd", procfile_filename(ff), s, (ssize_t)(ff->size - s));
r = read(ff->fd, &ff->data[s], ff->size - s);
if(unlikely(r == -1)) {
if(unlikely(!(ff->flags & PROCFILE_FLAG_NO_ERROR_ON_FILE_IO))) error(PF_PREFIX ": Cannot read from file '%s' on fd %d", procfile_filename(ff), ff->fd);
procfile_close(ff);
return NULL;
}
ff->len += r;
}
// debug(D_PROCFILE, "Rewinding file '%s'", ff->filename);
if(unlikely(lseek(ff->fd, 0, SEEK_SET) == -1)) {
if(unlikely(!(ff->flags & PROCFILE_FLAG_NO_ERROR_ON_FILE_IO))) error(PF_PREFIX ": Cannot rewind on file '%s'.", procfile_filename(ff));
procfile_close(ff);
return NULL;
}
pflines_reset(ff->lines);
pfwords_reset(ff->words);
procfile_parser(ff);
if(unlikely(procfile_adaptive_initial_allocation)) {
if(unlikely(ff->len > procfile_max_allocation)) procfile_max_allocation = ff->len;
if(unlikely(ff->lines->len > procfile_max_lines)) procfile_max_lines = ff->lines->len;
if(unlikely(ff->words->len > procfile_max_words)) procfile_max_words = ff->words->len;
}
// debug(D_PROCFILE, "File '%s' updated.", ff->filename);
return ff;
}
// ==============
// --- Poor man cycle counting.
static unsigned long tsc;
void begin_tsc(void)
{
unsigned long a, d;
asm volatile ("cpuid\nrdtsc" : "=a" (a), "=d" (d) : "0" (0) : "ebx", "ecx");
tsc = ((unsigned long)d << 32) | (unsigned long)a;
}
unsigned long end_tsc(void)
{
unsigned long a, d;
asm volatile ("rdtscp" : "=a" (a), "=d" (d) : : "ecx");
return (((unsigned long)d << 32) | (unsigned long)a) - tsc;
}
// ==============
unsigned long test_netdata_internal(void) {
static procfile *ff = NULL;
ff = procfile_reopen(ff, "/proc/self/status", " \t:,-()/", PROCFILE_FLAG_NO_ERROR_ON_FILE_IO);
if(!ff) {
fprintf(stderr, "Failed to open filename\n");
exit(1);
}
begin_tsc();
ff = procfile_readall(ff);
unsigned long c = end_tsc();
if(!ff) {
fprintf(stderr, "Failed to read filename\n");
exit(1);
}
return c;
}
unsigned long test_method1(void) {
static procfile *ff = NULL;
ff = procfile_reopen(ff, "/proc/self/status", " \t:,-()/", PROCFILE_FLAG_NO_ERROR_ON_FILE_IO);
if(!ff) {
fprintf(stderr, "Failed to open filename\n");
exit(1);
}
begin_tsc();
ff = procfile_readall1(ff);
unsigned long c = end_tsc();
if(!ff) {
fprintf(stderr, "Failed to read filename\n");
exit(1);
}
return c;
}
//--- Test
int main(int argc, char **argv)
{
(void)argc; (void)argv;
int i, max = 1000000;
unsigned long c1 = 0;
test_netdata_internal();
for(i = 0; i < max ; i++)
c1 += test_netdata_internal();
unsigned long c2 = 0;
test_method1();
for(i = 0; i < max ; i++)
c2 += test_method1();
printf("netdata internal: completed in %lu cycles, %lu cycles per read, %0.2f %%.\n", c1, c1 / max, (float)c1 * 100.0 / (float)c1);
printf("method1 : completed in %lu cycles, %lu cycles per read, %0.2f %%.\n", c2, c2 / max, (float)c2 * 100.0 / (float)c1);
return 0;
}
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