datatop/src/datatop_str.c

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/**
 * @file datatop_str.c
 * @brief Algorithms used for storing and polling data created.
 *
 * Methods created which store collected data from files in
 * dictionaries for many different file formats.
 */

#include <stdio.h>
#include <string.h>
#include "datatop_str.h"

/** @brief Reads an individual line from a file.
 *
 * Will read from buf2 until either a '\n' is reached, or the end of buf1
 * or buf2 is reached. The result is guaranteed to be null terminated.
 *
 * @param buf1 Destination buffer to store the read line.
 * @param len1 Size of destination buffer.
 * @param buf2 Source buffer to read lines from. Const, will not be
 *             modified by this function.
 * @param len2 Size of the source buffer.
 * @param start Offset (in bytes) to start reading from source buffer.
 * @return Length of line (of chars).
 */
int dt_read_line(char *buf1, int len1, const char *buf2, int len2, int start)
{
	int i, j;

	if (len1 < 1 || len2 < 1 || start < 0 || start > len2)
		return 0;

	if (buf1 == 0 || buf2 == 0)
		return 0;

	i = 0;
	j = start;

	while ((i < (len1-1)) && (j < len2)) {
		buf1[i] = buf2[j];
		if (buf1[i] == '\n')
			break;
		i++;
		j++;
	}
	buf1[i] = 0;
	return i;
}

/**
 * @brief Parses files that have Names and Values on separate lines.
 *
 * Use this method to parse files that have names on one line, followed by
 * the corresponding values on the next line. Such as "/proc/net/netstat"
 *
 * @param line1 First line that is parsed to store the datapoint names as keys.
 * @param len1 Length of line1.
 * @param line2 Second line that is parsed to store the datapoint values as dictionary values.
 * @param len2 Length of line2.
 * @param dict Dictionary that keys and values are added to.
 * @return Number of key/val pairs in the dictionary.
 */
int dt_parse_proc_dictionary(char *line1, int len1, char *line2,
			     int len2, struct dt_procdict *dict)
{
	int i, j, k;

	if (len1 < 1 || len2 < 1)
		return 0;

	if (line1 == 0 || line2 == 0 || dict == 0)
		return 0;

	k = 0;
	for (i = 0; i < len1 && k < DTOP_DICT_SIZE; i++) {
		if (line1[i] == ' ') {
			dict->key[k] = &line1[i+1];
			line1[i] = 0;
			k++;
		}
	}
	j = k;

	k = 0;
	for (i = 0; i < len2 && k < DTOP_DICT_SIZE; i++) {
		if (line2[i] == ' ') {
			dict->val[k] = &line2[i+1];
			line2[i] = 0;
			k++;
		}
	}
	if (j != k) {
		if (k < j)
			j = k;
		fprintf(stderr, "Warning, list index length mismatch\n");
	}
	dict->max = j;
	return j;
}

/**
 * @brief Parses line for prefixes for files that have individual data_point prefixes.
 *
 * Use this method for lines that have a prefix before data begins. Such as
 * "/proc/net/snmp"
 *
 * @param line1 Line to parse to find datapoint prefix.
 * @param len1 Length of line1.
 * @param dict Dictionary prefix is being added to.
 */
void dt_parse_for_prefix(char *line1, int len1, struct dt_procdict *dict)
{
	int i, j, k;

	if (len1 < 1)
		return;

	if (line1 == 0 || dict == 0)
		return;

	k = 0;
	for (i = 0; i < len1 && k < DTOP_DICT_SIZE; i++) {
		if (line1[i] == ' ') {
			dict->key[k] = &line1[i+1];
			line1[i] = 0;
			k++;
		}
	}

	for (j = 0; j < k; j++)
		dict->val[j] = &line1[0];

	for (j = 0; j < len1; j++) {
		if (line1[j] == ':')
			line1[j] = 0;
	}
}

/**
 * @brief Finds the dictionary index of a data_point name.
 *
 * @param str Name of data_point that is to be located in dict.
 * @param dict Dictionary to look through for dp name.
 * @return Dictionary index of name if found.
 * @return -1 if name not found in dictionary keys.
 */
int dt_find_dict_idx(const char *str, struct dt_procdict *dict)
{
	int i;
	if (str == 0 || dict == 0)
		return -1;

	for (i = 0; i < dict->max; i++) {
		if (dict->key[i] && !strcmp(str, dict->key[i]))
			return i;
	}
	return -1;
}

/**
 * @brief Parses files that have Names and Values on same line.
 *
 * Use this method to parse lines that have a dp name followed
 * by a dp value. Such as "/proc/net/snmp6"
 *
 * @param line1 Line to parse to find datapoint names and values.
 * @param len1 Length of line1.
 * @param l Index in the dictionary the key/val pair is added to.
 * @param dict Dictionary the keys and values are added to.
 * @return Number of key/val pairs in the dictionary.
 */
int dt_parse_proc_same_line_key_and_val(char *line1, int len1,
					int l, struct dt_procdict *dict)
{
	int i, k, n;
	if (len1 < 1)
		return 0;

	if (line1 == 0 || dict == 0)
		return 0;

	k = l;
	for (i = 0; i < len1 && k < DTOP_DICT_SIZE; i++) {
		if (line1[i] == ' ') {
			dict->key[k] = &line1[0];
			line1[i] = 0;
			for (n = i+1; n < len1; n++) {
				if (line1[n] != ' ') {
					dict->val[k] = &line1[n+1];
					break;
				}
			}
			break;
		}
	}
	k++;
	dict->max = k;
	return k;
}

/**
 * @brief Parses files that have a single line.
 *
 * Parses a single line file for csv, tab-separated, space-separated, and single
 * value formats and adds values to a dictionary. Such as
 * "/proc/sys/net/ipv4/ping_group_range"
 *
 * Use this method to parse lines that contain only values.
 *
 * @param line1 Line to parse.
 * @param len1 Length of line1.
 * @param dict Dictionary datapoints are added to.
 * @return Number of values dictionary holds.
 */
int dt_single_line_parse(char *line1, int len1, struct dt_procdict *dict)
{
	int i, k;
	k = 0;
	dict->val[k] = &line1[0];
	k++;

	for (i = 0; i < len1; i++) {
		if (line1[i] == ' ' || line1[i] == ',' || line1[i] == '	') {
			line1[i] = 0;
			dict->val[k] = &line1[i+1];
			k++;
		}
	}
	dict->max = k;
	return k;
}