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-rw-r--r--libnetdata/procfile/procfile.c472
1 files changed, 472 insertions, 0 deletions
diff --git a/libnetdata/procfile/procfile.c b/libnetdata/procfile/procfile.c
new file mode 100644
index 0000000..4a812ba
--- /dev/null
+++ b/libnetdata/procfile/procfile.c
@@ -0,0 +1,472 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "../libnetdata.h"
+
+#define PF_PREFIX "PROCFILE"
+
+#define PFWORDS_INCREASE_STEP 200
+#define PFLINES_INCREASE_STEP 10
+#define PROCFILE_INCREMENT_BUFFER 512
+
+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[0]) return ff->filename;
+
+ char buffer[FILENAME_MAX + 1];
+ snprintfz(buffer, FILENAME_MAX, "/proc/self/fd/%d", ff->fd);
+
+ ssize_t l = readlink(buffer, ff->filename, FILENAME_MAX);
+ if(unlikely(l == -1))
+ snprintfz(ff->filename, FILENAME_MAX, "unknown filename for fd %d", ff->fd);
+ else
+ ff->filename[l] = '\0';
+
+ // 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 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 pfwords *pfwords_new(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 pfwords_reset(pfwords *fw) {
+ // debug(D_PROCFILE, PF_PREFIX ": reseting words");
+ fw->len = 0;
+}
+
+static inline void pfwords_free(pfwords *fw) {
+ // debug(D_PROCFILE, PF_PREFIX ": freeing words");
+
+ freez(fw);
+}
+
+
+// ----------------------------------------------------------------------------
+// An array of lines
+
+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;
+}
+
+NEVERNULL
+static inline pflines *pflines_new(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 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);
+}
+
+
+// ----------------------------------------------------------------------------
+// The procfile
+
+void procfile_close(procfile *ff) {
+ if(unlikely(!ff)) return;
+
+ debug(D_PROCFILE, PF_PREFIX ": Closing file '%s'", procfile_filename(ff));
+
+ if(likely(ff->lines)) pflines_free(ff->lines);
+ if(likely(ff->words)) pfwords_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 = 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/
+ 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';
+ pfwords_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';
+ 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);
+ }
+ 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';
+ pfwords_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';
+ pfwords_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';
+ pfwords_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)) {
+ 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;
+}
+
+NOINLINE
+static void procfile_set_separators(procfile *ff, const char *separators) {
+ static PF_CHAR_TYPE def[256];
+ static char initilized = 0;
+
+ if(unlikely(!initilized)) {
+ // this is thread safe
+ // if initialized is zero, multiple threads may be executing
+ // this code at the same time, setting in def[] the exact same values
+ int i = 256;
+ while(i--) {
+ if(unlikely(i == '\n' || i == '\r'))
+ def[i] = PF_CHAR_IS_NEWLINE;
+
+ else if(unlikely(isspace(i) || !isprint(i)))
+ def[i] = PF_CHAR_IS_SEPARATOR;
+
+ else
+ def[i] = PF_CHAR_IS_WORD;
+ }
+
+ initilized = 1;
+ }
+
+ // copy the default
+ PF_CHAR_TYPE *ffs = ff->separators, *ffd = def, *ffe = &def[256];
+ while(ffd != ffe)
+ *ffs++ = *ffd++;
+
+ // set the separators
+ if(unlikely(!separators))
+ separators = " \t=|";
+
+ 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))) 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[0] = '\0';
+
+ ff->fd = fd;
+ ff->size = size;
+ ff->len = 0;
+ ff->flags = flags;
+
+ ff->lines = pflines_new();
+ ff->words = pfwords_new();
+
+ 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);
+ ff->filename[0] = '\0';
+ 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);
+ }
+ }
+}