/*
 * haproxy log time reporter
 *
 * Copyright 2000-2009 Willy Tarreau <w@1wt.eu>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 */

/*
 * gcc -O2 -o halog halog.c -Iinclude src/ebtree.c src/eb32tree.c
 *
 * Usage:
 *    $0 [ min_delay [ min_count [ field_shift ]]] < haproxy.log
 *    Note: if min_delay < 0, it only outputs lines with status codes 5xx.
 */

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>

#include <common/eb32tree.h>

#define ACCEPT_FIELD 6
#define TIME_FIELD 9
#define STATUS_FIELD 10
#define CONN_FIELD 15
#define MAXLINE 16384
#define QBITS 4

#define SKIP_CHAR(p,c) do { while (1) if (!*p) break; else if (*(p++) == c) break; } while (0)

/* [0] = err/date, [1] = req, [2] = conn, [3] = resp, [4] = data */
static struct eb_root timers[5] = {
	EB_ROOT_UNIQUE, EB_ROOT_UNIQUE, EB_ROOT_UNIQUE,
	EB_ROOT_UNIQUE, EB_ROOT_UNIQUE,
};

struct timer {
	struct eb32_node node;
	unsigned int count;
};


#define FILT_COUNT_ONLY		0x01
#define FILT_INVERT		0x02
#define FILT_QUIET		0x04
#define FILT_ERRORS_ONLY	0x08
#define FILT_ACC_DELAY		0x10
#define FILT_ACC_COUNT		0x20
#define FILT_GRAPH_TIMERS	0x40

unsigned int filter = 0;
unsigned int filter_invert = 0;
char line[MAXLINE];


void die(const char *msg)
{
	fprintf(stderr,
		"%s"
		"Usage: halog [-c] [-v] [-gt] [-s <skip>] [-e] [-ad <delay>] [-ac <count>] < file.log\n"
		"\n",
		msg ? msg : ""
		);
	exit(1);
}


/* return pointer to first char not part of current field starting at <p>. */
const char *field_stop(const char *p)
{
	unsigned char c;

	while (1) {
		c = *(p++);
		if (c > ' ')
			continue;
		if (c == ' ' || c == '\t' || c == 0)
			break;
	}
	return p - 1;
}

/* return field <field> (starting from 1) in string <p>. Only consider
 * contiguous spaces (or tabs) as one delimiter. May return pointer to
 * last char if field is not found. Equivalent to awk '{print $field}'.
 */
const char *field_start(const char *p, int field)
{
	unsigned char c;
	while (1) {
		/* skip spaces */
		while (1) {
			c = *p;
			if (c > ' ')
				break;
			if (c == ' ' || c == '\t')
				goto next;
			if (!c) /* end of line */
				return p;
			/* other char => new field */
			break;
		next:
			p++;
		}

		/* start of field */
		field--;
		if (!field)
			return p;

		/* skip this field */
		while (1) {
			c = *(p++);
			if (c > ' ')
				continue;
			if (c == ' ' || c == '\t')
				break;
			if (c == '\0')
				return p;
		}
	}
}

/* keep only the <bits> higher bits of <i> */
static inline unsigned int quantify_u32(unsigned int i, int bits)
{
	int high;

	if (!bits)
		return 0;

	if (i)
		high = fls_auto(i);    // 1 to 32
	else
		high = 0;

	if (high <= bits)
		return i;

	return i & ~((1 << (high - bits)) - 1);
}

/* keep only the <bits> higher bits of the absolute value of <i>, as well as
 * its sign. */
static inline int quantify(int i, int bits)
{
	if (i >= 0)
		return quantify_u32(i, bits);
	else
		return -quantify_u32(-i, bits);
}

/* Insert timer value <v> into tree <r>. A pre-allocated node must be passed
 * in <alloc>. It may be NULL, in which case the function will allocate it
 * itself. It will be reset to NULL once consumed. The caller is responsible
 * for freeing the node once not used anymore. The node where the value was
 * inserted is returned.
 */
struct timer *insert_timer(struct eb_root *r, struct timer **alloc, int v)
{
	struct timer *t = *alloc;
	struct eb32_node *n;

	if (!t) {
		t = calloc(sizeof(*t), 1);
		if (unlikely(!t)) {
			fprintf(stderr, "%s: not enough memory\n", __FUNCTION__);
			exit(1);
		}
	}
	t->node.key = quantify(v, QBITS);         // keep only the higher QBITS bits

	n = eb32i_insert(r, &t->node);
	if (n == &t->node)
		t = NULL;  /* node inserted, will malloc next time */

	*alloc = t;
	return container_of(n, struct timer, node);
}

/* Insert value value <v> into tree <r>. A pre-allocated node must be passed
 * in <alloc>. It may be NULL, in which case the function will allocate it
 * itself. It will be reset to NULL once consumed. The caller is responsible
 * for freeing the node once not used anymore. The node where the value was
 * inserted is returned.
 */
struct timer *insert_value(struct eb_root *r, struct timer **alloc, int v)
{
	struct timer *t = *alloc;
	struct eb32_node *n;

	if (!t) {
		t = calloc(sizeof(*t), 1);
		if (unlikely(!t)) {
			fprintf(stderr, "%s: not enough memory\n", __FUNCTION__);
			exit(1);
		}
	}
	t->node.key = v;

	n = eb32i_insert(r, &t->node);
	if (n == &t->node)
		t = NULL;  /* node inserted, will malloc next time */

	*alloc = t;
	return container_of(n, struct timer, node);
}

int str2ic(const char *s)
{
	int i = 0;
	int j, k;

	if (*s != '-') {
		/* positive number */
		while (1) {
			j = (*s++) - '0';
			k = i * 10;
			if ((unsigned)j > 9)
				break;
			i = k + j;
		}
	} else {
		/* negative number */
		s++;
		while (1) {
			j = (*s++) - '0';
			k = i * 10;
			if ((unsigned)j > 9)
				break;
			i = k - j;
		}
	}

	return i;
}


/* Equivalent to strtoul with a length. */
static inline unsigned int __strl2ui(const char *s, int len)
{
	unsigned int i = 0;
	while (len-- > 0) {
		i = i * 10 - '0';
		i += (unsigned char)*s++;
	}
	return i;
}

unsigned int strl2ui(const char *s, int len)
{
	return __strl2ui(s, len);
}

/* Convert "[04/Dec/2008:09:49:40.555]" to an integer equivalent to the time of
 * the day in milliseconds. It returns -1 for all unparsable values. The parser
 * looks ugly but gcc emits far better code that way.
 */
int convert_date(const char *field)
{
	unsigned int h, m, s, ms;
	unsigned char c;
	const char *b, *e;

	h = m = s = ms = 0;
	e = field;

	/* skip the date */
	while (1) {
		c = *(e++);
		if (c == ':')
			break;
		if (!c)
			goto out_err;
	}

	/* hour + ':' */
	b = e;
	while (1) {
		c = *(e++) - '0';
		if (c > 9)
			break;
		h = h * 10 + c;
	}
	if (c == (unsigned char)(0 - '0'))
		goto out_err;

	/* minute + ':' */
	b = e;
	while (1) {
		c = *(e++) - '0';
		if (c > 9)
			break;
		m = m * 10 + c;
	}
	if (c == (unsigned char)(0 - '0'))
		goto out_err;

	/* second + '.' or ']' */
	b = e;
	while (1) {
		c = *(e++) - '0';
		if (c > 9)
			break;
		s = s * 10 + c;
	}
	if (c == (unsigned char)(0 - '0'))
		goto out_err;

	/* if there's a '.', we have milliseconds */
	if (c == (unsigned char)('.' - '0')) {
		/* millisecond second + ']' */
		b = e;
		while (1) {
			c = *(e++) - '0';
			if (c > 9)
				break;
			ms = ms * 10 + c;
		}
		if (c == (unsigned char)(0 - '0'))
			goto out_err;
	}
	return (((h * 60) + m) * 60 + s) * 1000 + ms;
 out_err:
	return -1;
}

void truncated_line(int linenum, const char *line)
{
	if (!(filter & FILT_QUIET))
		fprintf(stderr, "Truncated line %d: %s\n", linenum, line);
}

int main(int argc, char **argv)
{
	const char *b, *e, *p;
	const char *output_file = NULL;
	int f, tot, last, linenum, err, parse_err;
	struct timer *t = NULL, *t2;
	struct eb32_node *n;
	int val, test;
	int array[5];
	int filter_acc_delay = 0, filter_acc_count = 0;
	int skip_fields = 1;

	argc--; argv++;
	while (argc > 0) {
		if (*argv[0] != '-')
			break;

		if (strcmp(argv[0], "-ad") == 0) {
			if (argc < 2) die("missing option for -ad");
			argc--; argv++;
			filter |= FILT_ACC_DELAY;
			filter_acc_delay = atol(*argv);
		}
		else if (strcmp(argv[0], "-ac") == 0) {
			if (argc < 2) die("missing option for -ac");
			argc--; argv++;
			filter |= FILT_ACC_COUNT;
			filter_acc_count = atol(*argv);
		}
		else if (strcmp(argv[0], "-s") == 0) {
			if (argc < 2) die("missing option for -s");
			argc--; argv++;
			skip_fields = atol(*argv);
		}
		else if (strcmp(argv[0], "-e") == 0)
			filter |= FILT_ERRORS_ONLY;
		else if (strcmp(argv[0], "-c") == 0)
			filter |= FILT_COUNT_ONLY;
		else if (strcmp(argv[0], "-q") == 0)
			filter |= FILT_QUIET;
		else if (strcmp(argv[0], "-v") == 0)
			filter_invert = !filter_invert;
		else if (strcmp(argv[0], "-gt") == 0)
			filter |= FILT_GRAPH_TIMERS;
		else if (strcmp(argv[0], "-o") == 0) {
			if (output_file)
				die("Fatal: output file name already specified.\n");
			if (argc < 2)
				die("Fatal: missing output file name.\n");
			output_file = argv[1];
		}
		argc--;
		argv++;
	}

	if (!filter)
		die("No action specified.\n");

	if (filter & FILT_ACC_COUNT && !filter_acc_count)
		filter_acc_count=1;

	if (filter & FILT_ACC_DELAY && !filter_acc_delay)
		filter_acc_delay = 1;

	linenum = 0;
	tot = 0;
	parse_err = 0;

	while (fgets(line, MAXLINE, stdin) != NULL) {
		linenum++;

		if (filter & FILT_ERRORS_ONLY) {
			/* only report erroneous status codes */
			b = field_start(line, STATUS_FIELD + skip_fields);
			if (!*b) {
				truncated_line(linenum, line);
				continue;
			}
			if (*b == '-') {
				test = 1;
			} else {
				val = strl2ui(b, 3);
				test = (val >= 500 && val <= 599);
			}
			test ^= filter_invert;
			if (test) {
				tot++;
				if (!(filter & FILT_COUNT_ONLY))
					printf("%s", line);
			}
			continue;
		}

		if (filter & (FILT_ACC_COUNT|FILT_ACC_DELAY)) {
			b = field_start(line, ACCEPT_FIELD + skip_fields);
			if (!*b) {
				truncated_line(linenum, line);
				continue;
			}

			val = convert_date(b);
			//printf("date=%s => %d\n", b, val);
			if (val < 0) {
				parse_err++;
				continue;
			}

			t2 = insert_value(&timers[0], &t, val);
			t2->count++;
			continue;
		}

		if (filter & FILT_GRAPH_TIMERS) {
			int f;

			b = field_start(line, TIME_FIELD + skip_fields);
			if (!*b) {
				truncated_line(linenum, line);
				continue;
			}

			e = field_stop(b + 1);
			/* we have field TIME_FIELD in [b]..[e-1] */

			p = b;
			err = 0;
			for (f = 0; f < 5 && *p; f++) {
				array[f] = str2ic(p);
				if (array[f] < 0) {
					array[f] = -1;
					err = 1;
				}

				SKIP_CHAR(p, '/');
			}

			if (f < 5) {
				parse_err++;
				continue;
			}

			/* if we find at least one negative time, we count one error
			 * with a time equal to the total session time. This will
			 * emphasize quantum timing effects associated to known
			 * timeouts. Note that on some buggy machines, it is possible
			 * that the total time is negative, hence the reason to reset
			 * it.
			 */
			if (err) {
				if (array[4] < 0)
					array[4] = -1;
				t2 = insert_timer(&timers[0], &t, array[4]);  // total time
				t2->count++;
			} else {
				int v;

				t2 = insert_timer(&timers[1], &t, array[0]); t2->count++;  // req
				t2 = insert_timer(&timers[2], &t, array[2]); t2->count++;  // conn
				t2 = insert_timer(&timers[3], &t, array[3]); t2->count++;  // resp

				v = array[4] - array[0] - array[1] - array[2] - array[3]; // data time
				if (v < 0 && !(filter & FILT_QUIET))
					fprintf(stderr, "ERR: %s (%d %d %d %d %d => %d)\n",
						line, array[0], array[1], array[2], array[3], array[4], v);
				t2 = insert_timer(&timers[4], &t, v); t2->count++;
			}
			continue;
		}

		/* all other cases mean we just want to count lines */
		tot++;
	}

	if (t)
		free(t);

	if (filter & FILT_COUNT_ONLY) {
		printf("%d\n", tot);
		exit(0);
	}

	if (filter & FILT_ERRORS_ONLY)
		exit(0);

	if (filter & (FILT_ACC_COUNT|FILT_ACC_DELAY)) {
		/* sort and count all timers. Output will look like this :
		 * <accept_date> <delta_ms from previous one> <nb entries>
		 */
		n = eb32_first(&timers[0]);

		if (n)
			last = n->key;
		while (n) {
			unsigned int d, h, m, s, ms;

			t = container_of(n, struct timer, node);
			h = n->key;
			d = h - last;
			last = h;

			if (d >= filter_acc_delay && t->count >= filter_acc_count) {
				ms = h % 1000; h = h / 1000;
				s = h % 60; h = h / 60;
				m = h % 60; h = h / 60;
				tot++;
				printf("%02d:%02d:%02d.%03d %d %d %d\n", h, m, s, ms, last, d, t->count);
			}
			n = eb32_next(n);
		}
	}
	else if (filter & FILT_GRAPH_TIMERS) {
		/* sort all timers */
		for (f = 0; f < 5; f++) {
			struct eb32_node *n;
			int val;

			val = 0;
			n = eb32_first(&timers[f]);
			while (n) {
				int i;
				double d;

				t = container_of(n, struct timer, node);
				last = n->key;
				val = t->count;

				i = (last < 0) ? -last : last;
				i = fls_auto(i) - QBITS;

				if (i > 0)
					d = val / (double)(1 << i);
				else
					d = val;

				if (d > 0.0) {
					printf("%d %d %f\n", f, last, d+1.0);
					tot++;
				}

				n = eb32_next(n);
			}
		}
	}

	if (!(filter & FILT_QUIET))
		fprintf(stderr, "%d lines in, %d lines out, %d parsing errors\n",
			linenum, tot, parse_err);
	exit(0);
}

/*
 * Local variables:
 *  c-indent-level: 8
 *  c-basic-offset: 8
 * End:
 */