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netdata_netdata/libnetdata/procfile/procfile.c
2023-01-25 19:04:07 +00:00

482 lines
15 KiB
C

// SPDX-License-Identifier: GPL-3.0-or-later
#include "../libnetdata.h"
#define PF_PREFIX "PROCFILE"
#define PFWORDS_INCREASE_STEP 2000
#define PFLINES_INCREASE_STEP 200
#define PROCFILE_INCREMENT_BUFFER 4096
int procfile_open_flags = O_RDONLY;
int procfile_adaptive_initial_allocation = 0;
// if adaptive allocation is set, these store the
// max values we have seen so far
size_t procfile_max_lines = PFLINES_INCREASE_STEP;
size_t procfile_max_words = PFWORDS_INCREASE_STEP;
size_t procfile_max_allocation = PROCFILE_INCREMENT_BUFFER;
// ----------------------------------------------------------------------------
char *procfile_filename(procfile *ff) {
if(ff->filename)
return ff->filename;
char filename[FILENAME_MAX + 1];
char buffer[FILENAME_MAX + 1];
snprintfz(buffer, FILENAME_MAX, "/proc/self/fd/%d", ff->fd);
ssize_t l = readlink(buffer, filename, FILENAME_MAX);
if(unlikely(l == -1))
snprintfz(filename, FILENAME_MAX, "unknown filename for fd %d", ff->fd);
else
filename[l] = '\0';
ff->filename = strdupz(filename);
// on non-linux systems, something like this will be needed
// fcntl(ff->fd, F_GETPATH, ff->filename)
return ff->filename;
}
// ----------------------------------------------------------------------------
// An array of words
static inline void procfile_words_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");
size_t minimum = PFWORDS_INCREASE_STEP;
size_t optimal = fw->size / 2;
size_t wanted = (optimal > minimum)?optimal:minimum;
ff->words = fw = reallocz(fw, sizeof(pfwords) + (fw->size + wanted) * sizeof(char *));
fw->size += wanted;
}
fw->words[fw->len++] = str;
}
NEVERNULL
static inline pfwords *procfile_words_create(void) {
// debug(D_PROCFILE, PF_PREFIX ": initializing words");
size_t size = (procfile_adaptive_initial_allocation) ? procfile_max_words : PFWORDS_INCREASE_STEP;
pfwords *new = mallocz(sizeof(pfwords) + size * sizeof(char *));
new->len = 0;
new->size = size;
return new;
}
static inline void procfile_words_reset(pfwords *fw) {
// debug(D_PROCFILE, PF_PREFIX ": resetting words");
fw->len = 0;
}
static inline void procfile_words_free(pfwords *fw) {
// debug(D_PROCFILE, PF_PREFIX ": freeing words");
freez(fw);
}
// ----------------------------------------------------------------------------
// An array of lines
NEVERNULL
static inline size_t *procfile_lines_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");
size_t minimum = PFLINES_INCREASE_STEP;
size_t optimal = fl->size / 2;
size_t wanted = (optimal > minimum)?optimal:minimum;
ff->lines = fl = reallocz(fl, sizeof(pflines) + (fl->size + wanted) * sizeof(ffline));
fl->size += wanted;
}
ffline *ffl = &fl->lines[fl->len++];
ffl->words = 0;
ffl->first = ff->words->len;
return &ffl->words;
}
NEVERNULL
static inline pflines *procfile_lines_create(void) {
// debug(D_PROCFILE, PF_PREFIX ": initializing lines");
size_t size = (unlikely(procfile_adaptive_initial_allocation)) ? procfile_max_words : PFLINES_INCREASE_STEP;
pflines *new = mallocz(sizeof(pflines) + size * sizeof(ffline));
new->len = 0;
new->size = size;
return new;
}
static inline void procfile_lines_reset(pflines *fl) {
// debug(D_PROCFILE, PF_PREFIX ": resetting lines");
fl->len = 0;
}
static inline void procfile_lines_free(pflines *fl) {
// debug(D_PROCFILE, PF_PREFIX ": freeing lines");
freez(fl);
}
// ----------------------------------------------------------------------------
// The procfile
void procfile_close(procfile *ff) {
if(unlikely(!ff)) return;
debug(D_PROCFILE, PF_PREFIX ": Closing file '%s'", procfile_filename(ff));
freez(ff->filename);
procfile_lines_free(ff->lines);
procfile_words_free(ff->words);
if(likely(ff->fd != -1)) close(ff->fd);
freez(ff);
}
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 = procfile_lines_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/
if(likely(ct == PF_CHAR_IS_WORD)) {
s++;
}
else if(likely(ct == PF_CHAR_IS_SEPARATOR)) {
if(!quote && !opened) {
if (s != t) {
// separator, but we have word before it
*s = '\0';
procfile_words_add(ff, t);
(*line_words)++;
t = ++s;
}
else {
// separator at the beginning
// skip it
t = ++s;
}
}
else {
// we are inside a quote or parenthesized string
s++;
}
}
else if(likely(ct == PF_CHAR_IS_NEWLINE)) {
// end of line
*s = '\0';
procfile_words_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 = procfile_lines_add(ff);
}
else if(likely(ct == 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';
procfile_words_add(ff, t);
(*line_words)++;
t = ++s;
}
else
s++;
}
else if(likely(ct == PF_CHAR_IS_OPEN)) {
if(s == t) {
opened++;
t = ++s;
}
else if(opened) {
opened++;
s++;
}
else
s++;
}
else if(likely(ct == PF_CHAR_IS_CLOSE)) {
if(opened) {
opened--;
if(!opened) {
*s = '\0';
procfile_words_add(ff, t);
(*line_words)++;
t = ++s;
}
else
s++;
}
else
s++;
}
else
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';
procfile_words_add(ff, t);
(*line_words)++;
// t = ++s;
}
}
procfile *procfile_readall(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)) {
size_t minimum = PROCFILE_INCREMENT_BUFFER;
size_t optimal = ff->size / 2;
size_t wanted = (optimal > minimum)?optimal:minimum;
debug(D_PROCFILE, PF_PREFIX ": Expanding data buffer for file '%s' by %zu bytes.", procfile_filename(ff), wanted);
ff = reallocz(ff, sizeof(procfile) + ff->size + wanted);
ff->size += wanted;
}
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))) collector_error(PF_PREFIX ": Cannot read from file '%s' on fd %d", procfile_filename(ff), ff->fd);
else if(unlikely(ff->flags & PROCFILE_FLAG_ERROR_ON_ERROR_LOG)) 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))) collector_error(PF_PREFIX ": Cannot rewind on file '%s'.", procfile_filename(ff));
else if(unlikely(ff->flags & PROCFILE_FLAG_ERROR_ON_ERROR_LOG)) error(PF_PREFIX ": Cannot rewind on file '%s'.", procfile_filename(ff));
procfile_close(ff);
return NULL;
}
procfile_lines_reset(ff->lines);
procfile_words_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;
}
static PF_CHAR_TYPE procfile_default_separators[256];
__attribute__((constructor)) void procfile_initialize_default_separators(void) {
int i = 256;
while(i--) {
if(unlikely(i == '\n' || i == '\r'))
procfile_default_separators[i] = PF_CHAR_IS_NEWLINE;
else if(unlikely(isspace(i) || !isprint(i)))
procfile_default_separators[i] = PF_CHAR_IS_SEPARATOR;
else
procfile_default_separators[i] = PF_CHAR_IS_WORD;
}
}
NOINLINE
static void procfile_set_separators(procfile *ff, const char *separators) {
// set the separators
if(unlikely(!separators))
separators = " \t=|";
// copy the default
memcpy(ff->separators, procfile_default_separators, 256 * sizeof(PF_CHAR_TYPE));
PF_CHAR_TYPE *ffs = ff->separators;
const char *s = separators;
while(*s)
ffs[(int)*s++] = PF_CHAR_IS_SEPARATOR;
}
void procfile_set_quotes(procfile *ff, const char *quotes) {
PF_CHAR_TYPE *ffs = ff->separators;
// remove all quotes
int i = 256;
while(i--)
if(unlikely(ffs[i] == PF_CHAR_IS_QUOTE))
ffs[i] = PF_CHAR_IS_WORD;
// if nothing given, return
if(unlikely(!quotes || !*quotes))
return;
// set the quotes
const char *s = quotes;
while(*s)
ffs[(int)*s++] = PF_CHAR_IS_QUOTE;
}
void procfile_set_open_close(procfile *ff, const char *open, const char *close) {
PF_CHAR_TYPE *ffs = ff->separators;
// remove all open/close
int i = 256;
while(i--)
if(unlikely(ffs[i] == PF_CHAR_IS_OPEN || ffs[i] == PF_CHAR_IS_CLOSE))
ffs[i] = PF_CHAR_IS_WORD;
// if nothing given, return
if(unlikely(!open || !*open || !close || !*close))
return;
// set the openings
const char *s = open;
while(*s)
ffs[(int)*s++] = PF_CHAR_IS_OPEN;
// set the closings
s = close;
while(*s)
ffs[(int)*s++] = PF_CHAR_IS_CLOSE;
}
procfile *procfile_open(const char *filename, const char *separators, uint32_t flags) {
debug(D_PROCFILE, PF_PREFIX ": Opening file '%s'", filename);
int fd = open(filename, procfile_open_flags, 0666);
if(unlikely(fd == -1)) {
if(unlikely(!(flags & PROCFILE_FLAG_NO_ERROR_ON_FILE_IO))) collector_error(PF_PREFIX ": Cannot open file '%s'", filename);
else if(unlikely(flags & PROCFILE_FLAG_ERROR_ON_ERROR_LOG)) error(PF_PREFIX ": Cannot open file '%s'", filename);
return NULL;
}
// info("PROCFILE: opened '%s' on fd %d", filename, fd);
size_t size = (unlikely(procfile_adaptive_initial_allocation)) ? procfile_max_allocation : PROCFILE_INCREMENT_BUFFER;
procfile *ff = mallocz(sizeof(procfile) + size);
//strncpyz(ff->filename, filename, FILENAME_MAX);
ff->filename = NULL;
ff->fd = fd;
ff->size = size;
ff->len = 0;
ff->flags = flags;
ff->lines = procfile_lines_create();
ff->words = procfile_words_create();
procfile_set_separators(ff, separators);
debug(D_PROCFILE, "File '%s' opened.", filename);
return ff;
}
procfile *procfile_reopen(procfile *ff, const char *filename, const char *separators, uint32_t flags) {
if(unlikely(!ff)) return procfile_open(filename, separators, flags);
if(likely(ff->fd != -1)) {
// info("PROCFILE: closing fd %d", ff->fd);
close(ff->fd);
}
ff->fd = open(filename, procfile_open_flags, 0666);
if(unlikely(ff->fd == -1)) {
procfile_close(ff);
return NULL;
}
// info("PROCFILE: opened '%s' on fd %d", filename, ff->fd);
//strncpyz(ff->filename, filename, FILENAME_MAX);
freez(ff->filename);
ff->filename = NULL;
ff->flags = flags;
// do not do the separators again if NULL is given
if(likely(separators)) procfile_set_separators(ff, separators);
return ff;
}
// ----------------------------------------------------------------------------
// example parsing of procfile data
void procfile_print(procfile *ff) {
size_t lines = procfile_lines(ff), l;
char *s;
(void)s;
debug(D_PROCFILE, "File '%s' with %zu lines and %zu words", procfile_filename(ff), ff->lines->len, ff->words->len);
for(l = 0; likely(l < lines) ;l++) {
size_t words = procfile_linewords(ff, l);
debug(D_PROCFILE, " line %zu starts at word %zu and has %zu words", l, ff->lines->lines[l].first, ff->lines->lines[l].words);
size_t w;
for(w = 0; likely(w < words) ;w++) {
s = procfile_lineword(ff, l, w);
debug(D_PROCFILE, " [%zu.%zu] '%s'", l, w, s);
}
}
}