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2658a437eb6d2d5c192e712d2808cc51134456ca
MaxScale/utils/skygw_utils.cc

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/*
* This file is distributed as part of the MariaDB Corporation MaxScale. It 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,
* version 2.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Copyright MariaDB Corporation Ab 2013-2014
*/
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <errno.h>
#include <string.h>
#include <time.h>
#include <stddef.h>
#include <regex.h>
#include "skygw_debug.h"
#include <skygw_types.h>
#include <sys/time.h>
#include "skygw_utils.h"
#if defined(MLIST)
static mlist_node_t* mlist_node_init(void* data, mlist_cursor_t* cursor);
//static mlist_node_t* mlist_node_get_next(mlist_node_t* curr_node);
//static mlist_node_t* mlist_get_first(mlist_t* list);
//static mlist_cursor_t* mlist_get_cursor(mlist_t* list);
#endif /* MLIST */
static slist_cursor_t* slist_cursor_init(
slist_t* list);
static slist_t* slist_init_ex(
bool create_cursors);
static slist_node_t* slist_node_init(
void* data,
slist_cursor_t* cursor);
static void slist_add_node(
slist_t* list,
slist_node_t* node);
#if defined(NOT_USED)
static slist_node_t* slist_node_get_next(
slist_node_t* curr_node);
static slist_node_t* slist_get_first(
slist_t* list);
static slist_cursor_t* slist_get_cursor(
slist_t* list);
#endif /*< NOT_USED */
static bool file_write_header(skygw_file_t* file);
static void simple_mutex_free_memory(simple_mutex_t* sm);
static void mlist_free_memory(mlist_t* ml, char* name);
static void thread_free_memory(skygw_thread_t* th, char* name);
/** End of static function declarations */
int atomic_add(
int *variable,
int value)
{
#ifdef __GNUC__
return (int) __sync_fetch_and_add (variable, value);
#else
asm volatile(
"lock; xaddl %%eax, %2;"
:"=a" (value)
: "a" (value), "m" (*variable)
: "memory" );
return value;
#endif
}
/** mutexed list, mlist */
#if defined(MLIST)
int skygw_rwlock_rdlock(
skygw_rwlock_t* rwlock)
{
int err = pthread_rwlock_rdlock(rwlock->srw_rwlock);
if (err == 0) {
rwlock->srw_rwlock_thr = pthread_self();
} else {
rwlock->srw_rwlock_thr = 0;
ss_dfprintf(stderr,
"* pthread_rwlock_rdlock : %s\n",
strerror(err));
}
return err;
}
int skygw_rwlock_wrlock(
skygw_rwlock_t* rwlock)
{
int err = pthread_rwlock_wrlock(rwlock->srw_rwlock);
if (err == 0) {
rwlock->srw_rwlock_thr = pthread_self();
} else {
rwlock->srw_rwlock_thr = 0;
ss_dfprintf(stderr,
"* pthread_rwlock_wrlock : %s\n",
strerror(err));
}
return err;
}
int skygw_rwlock_unlock(
skygw_rwlock_t* rwlock)
{
int err = pthread_rwlock_rdlock(rwlock->srw_rwlock);
if (err == 0) {
rwlock->srw_rwlock_thr = 0;
} else {
ss_dfprintf(stderr,
"* pthread_rwlock_unlock : %s\n",
strerror(err));
}
return err;
}
int skygw_rwlock_destroy(
skygw_rwlock_t* rwlock)
{
int err;
/** Lock */
if ((err = pthread_rwlock_wrlock(rwlock->srw_rwlock)) != 0)
{
fprintf(stderr,
"* Error : pthread_rwlock_wrlock failed due to %d, %s.\n",
err,
strerror(err));
goto retblock;
}
/** Clean the struct */
rwlock->srw_rwlock_thr = 0;
/** Unlock */
pthread_rwlock_unlock(rwlock->srw_rwlock);
/** Destroy */
if ((err = pthread_rwlock_destroy(rwlock->srw_rwlock)) != 0)
{
fprintf(stderr,
"* Error : pthread_rwlock_destroy failed due to %d,%s\n",
err,
strerror(err));
}
else
{
rwlock->srw_rwlock = NULL;
}
retblock:
return err;
}
int skygw_rwlock_init(
skygw_rwlock_t** rwlock)
{
skygw_rwlock_t* rwl;
int err;
rwl = (skygw_rwlock_t *)calloc(1, sizeof(skygw_rwlock_t));
if (rwl == NULL)
{
err = 1;
goto return_err;
}
rwl->srw_chk_top = CHK_NUM_RWLOCK;
rwl->srw_chk_tail = CHK_NUM_RWLOCK;
err = pthread_rwlock_init(rwl->srw_rwlock, NULL);
ss_dassert(err == 0);
if (err != 0)
{
free(rwl);
ss_dfprintf(stderr,
"* Creating pthread_rwlock failed : %s\n",
strerror(err));
goto return_err;
}
*rwlock = rwl;
return_err:
return err;
}
/**
* @node Cut off nodes of the list.
*
* Parameters:
* @param ml - <usage>
* <description>
*
* @return Pointer to the first of the detached nodes.
*
*
* @details (write detailed description here)
*
*/
mlist_node_t* mlist_detach_nodes(
mlist_t* ml)
{
mlist_node_t* node;
CHK_MLIST(ml);
node = ml->mlist_first;
ml->mlist_first = NULL;
ml->mlist_last = NULL;
ml->mlist_nodecount = 0;
return node;
}
/**
* @node Create a list with rwlock and optional read-only cursor
*
* Parameters:
* @param listp - <usage>
* <description>
*
* @param cursor - <usage>
* <description>
*
* @param name - <usage>
* <description>
*
* @return Address of mlist_t struct.
*
*
* @details Cursor must protect its reads with read lock, and after
* acquiring read lock reader must check whether the list is deleted
* (mlist_deleted).
*
*/
mlist_t* mlist_init(
mlist_t* listp,
mlist_cursor_t** cursor,
char* name,
void (*datadel)(void*),
int maxnodes)
{
mlist_cursor_t* c;
mlist_t* list;
if (cursor != NULL) {
ss_dassert(*cursor == NULL);
}
/** listp is not NULL if caller wants flat list */
if (listp == NULL) {
list = (mlist_t*)calloc(1, sizeof(mlist_t));
} else {
/** Caller wants list flat, memory won't be freed */
list = listp;
list->mlist_flat = true;
}
ss_dassert(list != NULL);
if (list == NULL) {
fprintf(stderr, "* Allocating memory for mlist failed\n");
mlist_free_memory(list, name);
goto return_list;
}
list->mlist_chk_top = CHK_NUM_MLIST;
list->mlist_chk_tail = CHK_NUM_MLIST;
/** Set size limit for list. 0 means unlimited */
list->mlist_nodecount_max = maxnodes;
/** Set data deletion callback fun */
list->mlist_datadel = datadel;
if (name != NULL) {
list->mlist_name = name;
}
/** Create mutex, return NULL if fails. */
if (simple_mutex_init(&list->mlist_mutex, "writebuf mutex") == NULL)
{
ss_dfprintf(stderr, "* Creating rwlock for mlist failed\n");
mlist_free_memory(list, name);
list = NULL;
goto return_list;
}
/** Create cursor for reading the list */
if (cursor != NULL) {
c = mlist_cursor_init(list);
if (c == NULL) {
simple_mutex_done(&list->mlist_mutex);
mlist_free_memory(list, name);
list = NULL;
goto return_list;
}
CHK_MLIST_CURSOR(c);
*cursor = c;
}
list->mlist_versno = 2; /*< vresno != 0 means that list is initialized */
CHK_MLIST(list);
return_list:
return list;
}
/**
* @node Free mlist memory allocations. name must be explicitly
* set if mlist has one.
*
* Parameters:
* @param ml - <usage>
* <description>
*
* @param name - <usage>
* <description>
*
* @return void
*
*
* @details (write detailed description here)
*
*/
static void mlist_free_memory(
mlist_t* ml,
char* name)
{
mlist_node_t* node;
/** name */
if (name != NULL) {
free(name);
}
if (ml != NULL) {
/** list data */
while(ml->mlist_first != NULL) {
/** Scan list and free nodes and data inside nodes */
node = ml->mlist_first->mlnode_next;
mlist_node_done(ml->mlist_first);
ml->mlist_first = node;
}
/** list structure */
if (!ml->mlist_flat) {
free(ml);
}
}
}
void mlist_node_done(
mlist_node_t* n)
{
CHK_MLIST_NODE(n);
if (n->mlnode_data != NULL) {
if (n->mlnode_list->mlist_datadel != NULL) {
(n->mlnode_list->mlist_datadel(n->mlnode_data));
}
free(n->mlnode_data);
}
free(n);
}
void* mlist_node_get_data(
mlist_node_t* node)
{
CHK_MLIST_NODE(node);
return node->mlnode_data;
}
mlist_cursor_t* mlist_cursor_init(
mlist_t* list)
{
CHK_MLIST(list);
mlist_cursor_t* c;
/** acquire shared lock to the list */
simple_mutex_lock(&list->mlist_mutex, true);
c = (mlist_cursor_t *)calloc(1, sizeof(mlist_cursor_t));
if (c == NULL) {
goto return_cursor;
}
c->mlcursor_chk_top = CHK_NUM_MLIST_CURSOR;
c->mlcursor_chk_tail = CHK_NUM_MLIST_CURSOR;
c->mlcursor_list = list;
/** Set cursor position if list is not empty */
if (list->mlist_first != NULL) {
c->mlcursor_pos = list->mlist_first;
}
simple_mutex_unlock(&list->mlist_mutex);
CHK_MLIST_CURSOR(c);
return_cursor:
return c;
}
/**
* @node Mark list as deleted and free the memory.
*
* Parameters:
* @param list - <usage>
* <description>
*
* @return void
*
*
* @details (write detailed description here)
*
*/
void mlist_done(
mlist_t* list)
{
CHK_MLIST(list);
simple_mutex_lock(&list->mlist_mutex, true);
list->mlist_deleted = true;
simple_mutex_unlock(&list->mlist_mutex);
simple_mutex_done(&list->mlist_mutex);
mlist_free_memory(list, list->mlist_name);
}
void* mlist_cursor_get_data_nomutex(
mlist_cursor_t* mc)
{
CHK_MLIST_CURSOR(mc);
return (mc->mlcursor_pos->mlnode_data);
}
/**
* @node Adds data to list by allocating node for it. Checks list size limit.
*
* Parameters:
* @param list - <usage>
* <description>
*
* @param data - <usage>
* <description>
*
* @return true, if succeed, false, if list had node limit and it is full.
*
*
* @details (write detailed description here)
*
*/
bool mlist_add_data_nomutex(
mlist_t* list,
void* data)
{
bool succp;
succp = mlist_add_node_nomutex(list, mlist_node_init(data, NULL));
return succp;
}
static mlist_node_t* mlist_node_init(
void* data,
mlist_cursor_t* cursor)
{
mlist_node_t* node;
node = (mlist_node_t*)calloc(1, sizeof(mlist_node_t));
node->mlnode_chk_top = CHK_NUM_MLIST_NODE;
node->mlnode_chk_tail = CHK_NUM_MLIST_NODE;
node->mlnode_data = data;
CHK_MLIST_NODE(node);
if (cursor != NULL) {
cursor->mlcursor_pos = node;
}
return node;
}
mlist_node_t* mlist_detach_first(
mlist_t* ml)
{
mlist_node_t* node;
CHK_MLIST(ml);
node = ml->mlist_first;
CHK_MLIST_NODE(node);
ml->mlist_first = node->mlnode_next;
node->mlnode_next = NULL;
ml->mlist_nodecount -= 1;
if (ml->mlist_nodecount == 0) {
ml->mlist_last = NULL;
} else {
CHK_MLIST_NODE(ml->mlist_first);
}
CHK_MLIST(ml);
return (node);
}
/**
* @node Add new node to end of list if there is space for it.
*
* Parameters:
* @param list - <usage>
* <description>
*
* @param newnode - <usage>
* <description>
*
* @param add_last - <usage>
* <description>
*
* @return true, if succeede, false, if list size limit was exceeded.
*
*
* @details (write detailed description here)
*
*/
bool mlist_add_node_nomutex(
mlist_t* list,
mlist_node_t* newnode)
{
bool succp = false;
CHK_MLIST(list);
CHK_MLIST_NODE(newnode);
ss_dassert(!list->mlist_deleted);
/** List is full already. */
if (list->mlist_nodecount == list->mlist_nodecount_max) {
goto return_succp;
}
/** Find location for new node */
if (list->mlist_last != NULL) {
ss_dassert(!list->mlist_last->mlnode_deleted);
CHK_MLIST_NODE(list->mlist_last);
CHK_MLIST_NODE(list->mlist_first);
ss_dassert(list->mlist_last->mlnode_next == NULL);
list->mlist_last->mlnode_next = newnode;
} else {
list->mlist_first = newnode;
}
list->mlist_last = newnode;
newnode->mlnode_list = list;
list->mlist_nodecount += 1;
succp = true;
return_succp:
CHK_MLIST(list);
return succp;
}
bool mlist_cursor_move_to_first(
mlist_cursor_t* mc)
{
bool succp = false;
mlist_t* list;
CHK_MLIST_CURSOR(mc);
list = mc->mlcursor_list;
CHK_MLIST(list);
simple_mutex_lock(&list->mlist_mutex, true);
if (mc->mlcursor_list->mlist_deleted) {
return false;
}
/** Set position point to first node */
mc->mlcursor_pos = list->mlist_first;
if (mc->mlcursor_pos != NULL) {
CHK_MLIST_NODE(mc->mlcursor_pos);
succp = true;
}
simple_mutex_unlock(&list->mlist_mutex);
return succp;
}
#endif /* MLIST */
/** End of mlist */
size_t get_timestamp_len(void)
{
return timestamp_len;
}
size_t get_timestamp_len_hp(void)
{
return timestamp_len_hp;
}
/**
* @node Generate and write a timestamp to location passed as argument
* by using at most tslen characters.
*
* Parameters:
* @param p_ts - in, use
* Write position in memory. Must be filled with at least
* <timestamp_len> zeroes
*
* @return Length of string written to p_ts. Length includes terminating '\0'.
*
*
* @details (write detailed description here)
*
*/
size_t snprint_timestamp(
char* p_ts,
size_t tslen)
{
time_t t;
struct tm tm;
size_t rval;
struct timeval tv;
if (p_ts == NULL) {
rval = 0;
goto retblock;
}
/** Generate timestamp */
t = time(NULL);
tm = *(localtime(&t));
snprintf(p_ts,
MIN(tslen,timestamp_len),
timestamp_formatstr,
tm.tm_year+1900,
tm.tm_mon+1,
tm.tm_mday,
tm.tm_hour,
tm.tm_min,
tm.tm_sec);
rval = strlen(p_ts)*sizeof(char);
retblock:
return rval;
}
/**
* @node Generate and write a timestamp to location passed as argument
* by using at most tslen characters. This will use millisecond precision.
*
* Parameters:
* @param p_ts - in, use
* Write position in memory. Must be filled with at least
* <timestamp_len> zeroes
*
* @return Length of string written to p_ts. Length includes terminating '\0'.
*
*
* @details (write detailed description here)
*
*/
size_t snprint_timestamp_hp(
char* p_ts,
size_t tslen)
{
time_t t;
struct tm tm;
size_t rval;
struct timeval tv;
int usec;
if (p_ts == NULL) {
rval = 0;
goto retblock;
}
/** Generate timestamp */
gettimeofday(&tv,NULL);
tm = *(localtime(&tv.tv_sec));
usec = tv.tv_usec/1000;
snprintf(p_ts,
MIN(tslen,timestamp_len_hp),
timestamp_formatstr_hp,
tm.tm_year+1900,
tm.tm_mon+1,
tm.tm_mday,
tm.tm_hour,
tm.tm_min,
tm.tm_sec,
usec);
rval = strlen(p_ts)*sizeof(char);
retblock:
return rval;
}
static slist_t* slist_init_ex(
bool create_cursors)
{
slist_t* list;
list = (slist_t*)calloc(1, sizeof(slist_t));
list->slist_chk_top = CHK_NUM_SLIST;
list->slist_chk_tail = CHK_NUM_SLIST;
if (create_cursors) {
list->slist_cursors_list = slist_init_ex(false);
}
return list;
}
static slist_node_t* slist_node_init(
void* data,
slist_cursor_t* cursor)
{
slist_node_t* node;
node = (slist_node_t*)calloc(1, sizeof(slist_node_t));
node->slnode_chk_top = CHK_NUM_SLIST_NODE;
node->slnode_chk_tail = CHK_NUM_SLIST_NODE;
node->slnode_data = data;
CHK_SLIST_NODE(node);
if (cursor != NULL) {
node->slnode_cursor_refcount += 1;
cursor->slcursor_pos = node;
}
return node;
}
static void slist_add_node(
slist_t* list,
slist_node_t* node)
{
CHK_SLIST(list);
CHK_SLIST_NODE(node);
if (list->slist_tail != NULL) {
CHK_SLIST_NODE(list->slist_tail);
CHK_SLIST_NODE(list->slist_head);
ss_dassert(list->slist_tail->slnode_next == NULL);
list->slist_tail->slnode_next = node;
} else {
list->slist_head = node;
}
list->slist_tail = node;
node->slnode_list = list;
list->slist_nelems += 1;
CHK_SLIST(list);
}
#if defined(NOT_USED)
static slist_node_t* slist_node_get_next(
slist_node_t* curr_node)
{
CHK_SLIST_NODE(curr_node);
if (curr_node->slnode_next != NULL) {
CHK_SLIST_NODE(curr_node->slnode_next);
return (curr_node->slnode_next);
}
return NULL;
}
static slist_node_t* slist_get_first(
slist_t* list)
{
CHK_SLIST(list);
if (list->slist_head != NULL) {
CHK_SLIST_NODE(list->slist_head);
return list->slist_head;
}
return NULL;
}
static slist_cursor_t* slist_get_cursor(
slist_t* list)
{
CHK_SLIST(list);
slist_cursor_t* c;
c = slist_cursor_init(list);
return c;
}
#endif /*< NOT_USED */
static slist_cursor_t* slist_cursor_init(
slist_t* list)
{
CHK_SLIST(list);
slist_cursor_t* c;
c = (slist_cursor_t *)calloc(1, sizeof(slist_cursor_t));
c->slcursor_chk_top = CHK_NUM_SLIST_CURSOR;
c->slcursor_chk_tail = CHK_NUM_SLIST_CURSOR;
c->slcursor_list = list;
/** Set cursor position is list is not empty */
if (list->slist_head != NULL) {
list->slist_head->slnode_cursor_refcount += 1;
c->slcursor_pos = list->slist_head;
}
/** Add cursor to cursor list */
slist_add_node(list->slist_cursors_list, slist_node_init(c, NULL));
CHK_SLIST_CURSOR(c);
return c;
}
/**
* @node Create a cursor and a list with cursors supported. 19.6.2013 :
* supports only cursor per list.
*
* Parameters:
* @param void - <usage>
* <description>
*
* @return returns a pointer to cursor, which is not positioned
* because the list is empty.
*
*
* @details (write detailed description here)
*
*/
slist_cursor_t* slist_init(void)
{
slist_t* list;
slist_cursor_t* slc;
list = slist_init_ex(true);
CHK_SLIST(list);
slc = slist_cursor_init(list);
CHK_SLIST_CURSOR(slc);
return slc;
}
/**
* @node moves cursor to the first node of list.
*
* Parameters:
* @param c - <usage>
* <description>
*
* @return true if there is first node in the list
* false is the list is empty.
*
*
* @details (write detailed description here)
*
*/
bool slcursor_move_to_begin(
slist_cursor_t* c)
{
bool succp = true;
slist_t* list;
CHK_SLIST_CURSOR(c);
list = c->slcursor_list;
CHK_SLIST(list);
c->slcursor_pos = list->slist_head;
if (c->slcursor_pos == NULL) {
succp = false;
}
return succp;
}
/**
* @node moves cursor to next node
*
* Parameters:
* @param c - <usage>
* <description>
*
* @return true in success, false is there is no next node on the list.
*
*
* @details (write detailed description here)
*
*/
bool slcursor_step_ahead(
slist_cursor_t* c)
{
bool succp = false;
slist_node_t* node;
CHK_SLIST_CURSOR(c);
CHK_SLIST_NODE(c->slcursor_pos);
node = c->slcursor_pos->slnode_next;
if (node != NULL) {
CHK_SLIST_NODE(node);
c->slcursor_pos = node;
succp = true;
}
return succp;
}
void* slcursor_get_data(
slist_cursor_t* c)
{
slist_node_t* node;
void* data = NULL;
CHK_SLIST_CURSOR(c);
node = c->slcursor_pos;
if (node != NULL) {
CHK_SLIST_NODE(node);
data = node->slnode_data;
}
return data;
}
/**
* @node Add data to the list by using cursor.
*
* Parameters:
* @param c - <usage>
* <description>
*
* @param data - <usage>
* <description>
*
* @return void
*
*
* @details (write detailed description here)
*
*/
void slcursor_add_data(
slist_cursor_t* c,
void* data)
{
slist_t* list;
slist_node_t* pos;
CHK_SLIST_CURSOR(c);
list = c->slcursor_list;
CHK_SLIST(list);
if (c->slcursor_pos != NULL)
{
CHK_SLIST_NODE(c->slcursor_pos);
}
ss_dassert(list->slist_tail->slnode_next == NULL);
pos = slist_node_init(data, c);
slist_add_node(list, pos);
CHK_SLIST(list);
CHK_SLIST_CURSOR(c);
}
/**
* Remove the node currently pointed by the cursor from the slist. This does not delete the data in the
* node but will delete the structure pointing to that data. This is useful when
* the user wants to free the allocated memory. After node removal, the cursor
* will point to the node before the removed node.
* @param c Cursor pointing to the data node to be removed
*/
void slcursor_remove_data(slist_cursor_t* c)
{
slist_node_t* node = c->slcursor_pos;
int havemore = slist_size(c);
slcursor_move_to_begin (c);
if(node == c->slcursor_pos)
{
c->slcursor_list->slist_head = c->slcursor_list->slist_head->slnode_next;
slcursor_move_to_begin (c);
atomic_add((int*)&node->slnode_list->slist_nelems,-1);
atomic_add((int*)&node->slnode_cursor_refcount,-1);
if(node->slnode_cursor_refcount == 0)
{
free(node);
}
return;
}
while(havemore)
{
if( c->slcursor_pos->slnode_next == node)
{
c->slcursor_pos->slnode_next = node->slnode_next;
atomic_add((int*)&node->slnode_list->slist_nelems,-1);
atomic_add((int*)&node->slnode_cursor_refcount,-1);
if(node->slnode_cursor_refcount == 0)
{
free(node);
}
return;
}
havemore = slcursor_step_ahead (c);
}
}
/**
* Return the size of the slist.
* @param c slist cursor which refers to a list
* @return nummber of elements in the list
*/
size_t slist_size(slist_cursor_t* c)
{
return c->slcursor_list->slist_nelems;
}
void slist_done(
slist_cursor_t* c)
{
bool succp;
void* data;
succp = slcursor_move_to_begin(c);
while (succp) {
data = slcursor_get_data(c);
free(data);
succp = slcursor_step_ahead(c);
}
free(c->slcursor_list);
free(c);
}
/** End of list implementation */
/**
* @node Initialize thread data structure
*
* Parameters:
* @param name copy is taken and stored to thread structure
*
* @param sth_thrfun - <usage>
* <description>
*
* @param data thread data pointer
*
* @return thread pointer or NULL in case of failure
*
*
* @details (write detailed description here)
*
*/
skygw_thread_t* skygw_thread_init(
const char* name,
void* (*sth_thrfun)(void* data),
void* data)
{
skygw_thread_t* th =
(skygw_thread_t *)calloc(1, sizeof(skygw_thread_t));
if (th == NULL) {
fprintf(stderr, "* Memory allocation for thread failed\n");
goto return_th;
}
ss_dassert(th != NULL);
th->sth_chk_top = CHK_NUM_THREAD;
th->sth_chk_tail = CHK_NUM_THREAD;
th->sth_parent = pthread_self();
ss_debug(th->sth_state = THR_INIT;)
th->sth_name = strndup(name, PATH_MAX);
th->sth_mutex = simple_mutex_init(NULL, name);
if (th->sth_mutex == NULL) {
thread_free_memory(th, th->sth_name);
th = NULL;
goto return_th;
}
th->sth_thrfun = sth_thrfun;
th->sth_data = data;
CHK_THREAD(th);
return_th:
return th;
}
static void thread_free_memory(
skygw_thread_t* th,
char* name)
{
if (name != NULL) {
free(name);
}
free(th);
}
/**
* @node Release skygw_thread data except filewriter.
*
* Parameters:
* @param th - <usage>
* <description>
*
* @return void
*
*
* @details (write detailed description here)
*
*/
void skygw_thread_done(
skygw_thread_t* th)
{
if (th != NULL) {
CHK_THREAD(th);
ss_dassert(th->sth_state == THR_STOPPED);
ss_debug(th->sth_state = THR_DONE;)
simple_mutex_done(th->sth_mutex);
pthread_join(th->sth_thr, NULL);
thread_free_memory(th, th->sth_name);
}
}
pthread_t skygw_thread_gettid(
skygw_thread_t* thr)
{
CHK_THREAD(thr);
return thr->sth_thr;
}
int skygw_thread_start(
skygw_thread_t* thr)
{
int err;
CHK_THREAD(thr);
err = pthread_create(&thr->sth_thr,
NULL,
thr->sth_thrfun,
thr);
ss_dassert(err == 0);
if (err != 0) {
fprintf(stderr,
"* Starting file writer thread failed due error, "
"%d, %s\n",
err,
strerror(errno));
goto return_err;
}
return_err:
return err;
}
#if defined(SS_DEBUG)
skygw_thr_state_t skygw_thread_get_state(
skygw_thread_t* thr)
{
CHK_THREAD(thr);
return thr->sth_state;
}
#endif
/**
* @node Update thread state
*
* Parameters:
* @param thr - <usage>
* <description>
*
* @param state - <usage>
* <description>
*
* @return void
*
*
* @details Thread must check state with mutex.
*
*/
#if defined(SS_DEBUG)
void skygw_thread_set_state(
skygw_thread_t* thr,
skygw_thr_state_t state)
{
CHK_THREAD(thr);
simple_mutex_lock(thr->sth_mutex, true);
thr->sth_state = state;
simple_mutex_unlock(thr->sth_mutex);
}
#endif
/**
* @node Set exit flag for thread from other thread
*
* Parameters:
* @param thr - <usage>
* <description>
*
* @return
*
*
* @details This call informs thread about exit flag and waits the response.
*
*/
bool skygw_thread_set_exitflag(
skygw_thread_t* thr,
skygw_message_t* sendmes,
skygw_message_t* recmes)
{
bool succp = false;
/**
* If thread struct pointer is NULL there's running thread
* neither.
*/
if (thr == NULL) {
succp = true;
goto return_succp;
}
CHK_THREAD(thr);
CHK_MESSAGE(sendmes);
CHK_MESSAGE(recmes);
simple_mutex_lock(thr->sth_mutex, true);
succp = !thr->sth_must_exit;
thr->sth_must_exit = true;
simple_mutex_unlock(thr->sth_mutex);
/** Inform thread and wait for response */
if (succp) {
skygw_message_send(sendmes);
skygw_message_wait(recmes);
}
ss_dassert(thr->sth_state == THR_STOPPED);
return_succp:
return succp;
}
void* skygw_thread_get_data(
skygw_thread_t* thr)
{
CHK_THREAD(thr);
return thr->sth_data;
}
bool skygw_thread_must_exit(
skygw_thread_t* thr)
{
CHK_THREAD(thr);
return thr->sth_must_exit;
}
void acquire_lock(
int* l)
{
register int misscount = 0;
struct timespec ts1;
ts1.tv_sec = 0;
while (atomic_add(l, 1) != 0) {
atomic_add(l, -1);
misscount += 1;
if (misscount > 10)
{
ts1.tv_nsec = (rand()%misscount)*1000000;
nanosleep(&ts1, NULL);
}
}
}
void release_lock(
int* l)
{
atomic_add(l, -1);
}
/**
* @node Create a simple_mutex structure which encapsulates pthread_mutex.
*
* Parameters:
* @param mutexptr if mutex is initialized within caller's memory, this is
* the address for it. If mutex is flat, there is value, otherwise it is NULL.
*
* @param name name of mutex, passed argument is copied and pointer is stored
* to mutex struct.
*
* @return simple_mutex pointer or NULL in case of failure.
*
*
* @details If mutex is flat, sm_enabled can be read if the memory is not freed.
* If flat mutex exists, sm_enabled is true.
* If mutex allocates its own memory, the pointer is NULL if mutex doesn't
* exist.
*
*/
simple_mutex_t* simple_mutex_init(
simple_mutex_t* mutexptr,
const char* name)
{
int err;
simple_mutex_t* sm;
/** Copy pointer only if flat, allocate memory otherwise. */
if (mutexptr != NULL) {
sm = mutexptr;
sm->sm_flat = true;
} else {
sm = (simple_mutex_t *)calloc(1, sizeof(simple_mutex_t));
}
ss_dassert(sm != NULL);
#if defined(SS_DEBUG)
sm->sm_chk_top = CHK_NUM_SIMPLE_MUTEX;
sm->sm_chk_tail = CHK_NUM_SIMPLE_MUTEX;
#endif
sm->sm_name = strndup(name, PATH_MAX);
/** Create pthread mutex */
err = pthread_mutex_init(&sm->sm_mutex, NULL);
if (err != 0) {
fprintf(stderr,
"* Initializing simple mutex %s failed due error "
"%d, %s\n",
name,
err,
strerror(errno));
perror("simple_mutex : ");
/** Write zeroes if flat, free otherwise. */
if (sm->sm_flat) {
memset(sm, 0, sizeof(*sm));
} else {
simple_mutex_free_memory(sm);
sm = NULL;
}
goto return_sm;
}
sm->sm_enabled = true;
CHK_SIMPLE_MUTEX(sm);
return_sm:
return sm;
}
int simple_mutex_done(
simple_mutex_t* sm)
{
int err = 0;
CHK_SIMPLE_MUTEX(sm);
if (atomic_add(&sm->sm_enabled, -1) != 1) {
atomic_add(&sm->sm_enabled, 1);
}
err = pthread_mutex_destroy(&sm->sm_mutex);
#if defined(NOT_USED)
if (err != 0) {
perror("simple_mutex : ");
fprintf(stderr,
"* Destroying simple mutex %s failed due "
"%d, %s\n",
sm->sm_name,
err,
strerror(errno));
goto return_err;
}
#endif
simple_mutex_free_memory(sm);
#if defined(NOT_USED)
return_err:
#endif
return err;
}
static void simple_mutex_free_memory(
simple_mutex_t* sm)
{
if (sm->sm_name != NULL) {
free(sm->sm_name);
}
if (!sm->sm_flat) {
free(sm);
}
}
int simple_mutex_lock(
simple_mutex_t* sm,
bool block)
{
int err;
/**
* Leaving the following serves as a reminder. It may assert
* any given time because sm_lock_thr is not protected.
*
* ss_dassert(sm->sm_lock_thr != pthread_self());
*/
if (block) {
err = pthread_mutex_lock(&sm->sm_mutex);
} else {
err = pthread_mutex_trylock(&sm->sm_mutex);
}
if (err != 0) {
fprintf(stderr,
"* Locking simple mutex %s failed due error, "
"%d, %s\n",
sm->sm_name,
err,
strerror(errno));
perror("simple_mutex : ");
} else {
/**
* Note that these updates are not protected.
*/
sm->sm_locked = true;
sm->sm_lock_thr = pthread_self();
}
return err;
}
int simple_mutex_unlock(
simple_mutex_t* sm)
{
int err;
/**
* Leaving the following serves as a reminder. It may assert
* any given time because sm_lock_thr is not protected.
*
* ss_dassert(sm->sm_lock_thr == pthread_self());
*/
err = pthread_mutex_unlock(&sm->sm_mutex);
if (err != 0) {
fprintf(stderr,
"* Unlocking simple mutex %s failed due error "
"%d, %s\n",
sm->sm_name,
err,
strerror(errno));
perror("simple_mutex : ");
} else {
/**
* Note that these updates are not protected.
*/
sm->sm_locked = false;
sm->sm_lock_thr = 0;
}
return err;
}
skygw_message_t* skygw_message_init(void)
{
int err;
skygw_message_t* mes;
mes = (skygw_message_t*)calloc(1, sizeof(skygw_message_t));
if (mes == NULL)
{
err = 1;
goto return_mes;
}
mes->mes_chk_top = CHK_NUM_MESSAGE;
mes->mes_chk_tail = CHK_NUM_MESSAGE;
err = pthread_mutex_init(&(mes->mes_mutex), NULL);
if (err != 0) {
fprintf(stderr,
"* Initializing pthread mutex failed due error "
"%d, %s\n",
err,
strerror(errno));
free(mes);
mes = NULL;
goto return_mes;
}
err = pthread_cond_init(&(mes->mes_cond), NULL);
if (err != 0) {
fprintf(stderr,
"* Initializing pthread cond var failed, "
"due error %d, %s\n",
err,
strerror(errno));
pthread_mutex_destroy(&mes->mes_mutex);
free(mes);
mes = NULL;
goto return_mes;
}
CHK_MESSAGE(mes);
return_mes:
return mes;
}
void skygw_message_done(
skygw_message_t* mes)
{
int err;
/**
* If message struct pointer is NULL there's nothing to free.
*/
if (mes == NULL) {
return;
}
CHK_MESSAGE(mes);
err = pthread_cond_destroy(&(mes->mes_cond));
if (err != 0) {
fprintf(stderr,
"* Destroying cond var failed due error %d, %s\n",
err,
strerror(errno));
}
ss_dassert(err == 0);
err = pthread_mutex_destroy(&(mes->mes_mutex));
if (err != 0) {
fprintf(stderr,
"* Destroying pthread mutex failed, "
"due error %d, %s\n",
err,
strerror(errno));
}
ss_dassert(err == 0);
free(mes);
}
skygw_mes_rc_t skygw_message_send(
skygw_message_t* mes)
{
int err;
skygw_mes_rc_t rc = MES_RC_FAIL;
CHK_MESSAGE(mes);
err = pthread_mutex_lock(&(mes->mes_mutex));
if (err != 0) {
fprintf(stderr,
"* Locking pthread mutex failed, "
"due to error %d, %s\n",
err,
strerror(errno));
goto return_mes_rc;
}
mes->mes_sent = true;
err = pthread_cond_signal(&(mes->mes_cond));
if (err == 0)
{
rc = MES_RC_SUCCESS;
}
else
{
fprintf(stderr,
"* Signaling pthread cond var failed, "
"due to error %d, %s\n",
err,
strerror(errno));
}
err = pthread_mutex_unlock(&(mes->mes_mutex));
if (err != 0)
{
fprintf(stderr,
"* Unlocking pthread mutex failed, "
"due to error %d, %s\n",
err,
strerror(errno));
}
return_mes_rc:
return rc;
}
void skygw_message_wait(
skygw_message_t* mes)
{
int err;
CHK_MESSAGE(mes);
err = pthread_mutex_lock(&(mes->mes_mutex));
if (err != 0) {
fprintf(stderr,
"* Locking pthread mutex failed, "
"due error %d, %s\n",
err,
strerror(errno));
}
ss_dassert(err == 0);
while (!mes->mes_sent) {
err = pthread_cond_wait(&(mes->mes_cond), &(mes->mes_mutex));
if (err != 0) {
fprintf(stderr,
"* Locking pthread cond wait failed, "
"due error %d, %s\n",
err,
strerror(errno));
}
}
mes->mes_sent = false;
err = pthread_mutex_unlock(&(mes->mes_mutex));
if (err != 0) {
fprintf(stderr,
"* Unlocking pthread mutex failed, "
"due error %d, %s\n",
err,
strerror(errno));
}
ss_dassert(err == 0);
}
void skygw_message_reset(
skygw_message_t* mes)
{
int err;
CHK_MESSAGE(mes);
err = pthread_mutex_lock(&(mes->mes_mutex));
if (err != 0) {
fprintf(stderr,
"* Locking pthread mutex failed, "
"due error %d, %s\n",
err,
strerror(errno));
goto return_mes_rc;
}
ss_dassert(err == 0);
mes->mes_sent = false;
err = pthread_mutex_unlock(&(mes->mes_mutex));
if (err != 0) {
fprintf(stderr,
"* Unlocking pthread mutex failed, "
"due error %d, %s\n",
err,
strerror(errno));
goto return_mes_rc;
}
return_mes_rc:
ss_dassert(err == 0);
}
static bool file_write_header(
skygw_file_t* file)
{
bool succp = false;
size_t wbytes1;
size_t wbytes2;
size_t wbytes3;
size_t wbytes4;
size_t len1;
size_t len2;
size_t len3;
size_t len4;
const char* header_buf1;
char* header_buf2 = NULL;
char* header_buf3 = NULL;
const char* header_buf4;
time_t* t;
struct tm* tm;
#if defined(LAPTOP_TEST)
struct timespec ts1;
ts1.tv_sec = 0;
ts1.tv_nsec = DISKWRITE_LATENCY*1000000;
#endif
t = (time_t *)malloc(sizeof(time_t));
tm = (struct tm *)malloc(sizeof(struct tm));
*t = time(NULL);
*tm = *localtime(t);
CHK_FILE(file);
header_buf1 = "\n\nMariaDB Corporation MaxScale\t";
header_buf2 = (char *)calloc(1, strlen(file->sf_fname)+2);
snprintf(header_buf2, strlen(file->sf_fname)+2, "%s ", file->sf_fname);
header_buf3 = strdup(asctime(tm));
header_buf4 = "------------------------------------------------------"
"-----------------\n";
if (header_buf2 == NULL) {
goto return_succp;
}
if (header_buf3 == NULL) {
goto return_succp;
}
len1 = strlen(header_buf1);
len2 = strlen(header_buf2);
len3 = strlen(header_buf3);
len4 = strlen(header_buf4);
#if defined(LAPTOP_TEST)
nanosleep(&ts1, NULL);
#else
wbytes1=fwrite((void*)header_buf1, len1, 1, file->sf_file);
wbytes2=fwrite((void*)header_buf2, len2, 1, file->sf_file);
wbytes3=fwrite((void*)header_buf3, len3, 1, file->sf_file);
wbytes4=fwrite((void*)header_buf4, len4, 1, file->sf_file);
if (wbytes1 != 1 || wbytes2 != 1 || wbytes3 != 1 || wbytes4 != 1) {
fprintf(stderr,
"\nError : Writing header %s %s %s %s failed.\n",
header_buf1,
header_buf2,
header_buf3,
header_buf4);
perror("Logfile header write");
goto return_succp;
}
#endif
CHK_FILE(file);
succp = true;
return_succp:
if (header_buf2 != NULL) {
free(header_buf2);
}
if (header_buf3 != NULL) {
free(header_buf3);
}
free(t);
free(tm);
return succp;
}
static bool file_write_footer(
skygw_file_t* file,
bool shutdown)
{
bool succp = false;
size_t wbytes1;
size_t wbytes3;
size_t wbytes4;
size_t len1;
size_t len4;
int tslen;
const char* header_buf1;
char* header_buf3 = NULL;
const char* header_buf4;
#if defined(LAPTOP_TEST)
struct timespec ts1;
ts1.tv_sec = 0;
ts1.tv_nsec = DISKWRITE_LATENCY*1000000;
#endif
CHK_FILE(file);
if (shutdown)
{
header_buf1 = "MaxScale is shut down.\t";
}
else
{
header_buf1 = "Closed file due log rotation.\t";
}
tslen = get_timestamp_len();
header_buf3 = (char *)malloc(tslen);
if (header_buf3 == NULL)
{
goto return_succp;
}
tslen = snprint_timestamp(header_buf3, tslen);
header_buf4 = "\n--------------------------------------------"
"---------------------------\n";
len1 = strlen(header_buf1);
len4 = strlen(header_buf4);
#if defined(LAPTOP_TEST)
nanosleep(&ts1, NULL);
#else
wbytes3=fwrite((void*)header_buf3, tslen, 1, file->sf_file);
wbytes1=fwrite((void*)header_buf1, len1, 1, file->sf_file);
wbytes4=fwrite((void*)header_buf4, len4, 1, file->sf_file);
if (wbytes1 != 1 || wbytes3 != 1 || wbytes4 != 1)
{
fprintf(stderr,
"\nError : Writing header %s %s to %s failed.\n",
header_buf1,
header_buf3,
header_buf4);
perror("Logfile header write");
goto return_succp;
}
#endif
CHK_FILE(file);
succp = true;
return_succp:
if (header_buf3 != NULL)
{
free(header_buf3);
}
return succp;
}
/**
* Write data to a file.
*
* @param file write target
* @param data pointer to contiguous memory buffer
* @param nbytes amount of bytes to be written
* @param flush ensure that write is permanent
*
* @return 0 if succeed, errno if failed.
*/
int skygw_file_write(
skygw_file_t* file,
void* data,
size_t nbytes,
bool flush)
{
int rc;
#if !defined(LAPTOP_TEST)
int err = 0;
size_t nwritten;
int fd;
static int writecount;
#else
struct timespec ts1;
ts1.tv_sec = 0;
ts1.tv_nsec = DISKWRITE_LATENCY*1000000;
#endif
CHK_FILE(file);
#if defined(LAPTOP_TEST)
nanosleep(&ts1, NULL);
#else
nwritten = fwrite(data, nbytes, 1, file->sf_file);
if (nwritten != 1) {
rc = errno;
perror("Logfile write.\n");
fprintf(stderr,
"* Writing %ld bytes,\n%s\n to %s failed.\n",
nbytes,
(char *)data,
file->sf_fname);
goto return_rc;
}
writecount += 1;
if (flush || writecount == FSYNCLIMIT)
{
fd = fileno(file->sf_file);
err = fflush(file->sf_file);
err = fsync(fd);
writecount = 0;
}
#endif
rc = 0;
CHK_FILE(file);
return_rc:
return rc;
}
skygw_file_t* skygw_file_alloc(
char* fname)
{
skygw_file_t* file;
if ((file = (skygw_file_t *)calloc(1, sizeof(skygw_file_t))) == NULL)
{
fprintf(stderr,
"* Error : Memory allocation for file %s failed.\n",
fname);
perror("SkyGW file allocation\n");
return NULL;
}
ss_dassert(file != NULL);
file->sf_chk_top = CHK_NUM_FILE;
file->sf_chk_tail = CHK_NUM_FILE;
file->sf_fname = strdup(fname);
return file;
}
skygw_file_t* skygw_file_init(
char* fname,
char* symlinkname)
{
skygw_file_t* file;
if ((file = skygw_file_alloc (fname)) == NULL)
{
/** Error was reported in skygw_file_alloc */
goto return_file;
}
if ((file->sf_file = fopen(file->sf_fname, "a")) == NULL)
{
int eno = errno;
errno = 0;
fprintf(stderr,
"* Opening file %s failed due %d, %s.\n",
file->sf_fname,
eno,
strerror(eno));
free(file);
file = NULL;
goto return_file;
}
setvbuf(file->sf_file, NULL, _IONBF, 0);
if (!file_write_header(file))
{
int eno = errno;
errno = 0;
fprintf(stderr,
"\nError : Writing header of log file %s failed due %d, %s.\n",
file->sf_fname,
eno,
strerror(eno));
free(file);
file = NULL;
goto return_file;
}
CHK_FILE(file);
ss_dfprintf(stderr, "Opened %s\n", file->sf_fname);
/**
* Create symlink to newly created file if name was provided.
*/
if (symlinkname != NULL)
{
int rc;
unlink(symlinkname);
rc = symlink(fname, symlinkname);
if (rc != 0)
{
int eno = errno;
errno = 0;
fprintf(stderr,
"failed to create symlink %s -> "
"%s due %d, %s. Exiting.",
fname,
symlinkname,
eno,
strerror(eno));
free(file);
file = NULL;
goto return_file;
}
}
return_file:
return file;
}
void skygw_file_free(skygw_file_t* file)
{
if(file)
{
free(file->sf_fname);
free(file);
}
}
void skygw_file_close(
skygw_file_t* file,
bool shutdown)
{
int fd;
int err;
if (file != NULL)
{
CHK_FILE(file);
if (!file_write_footer(file, shutdown))
{
fprintf(stderr,
"* Writing footer to log file %s failed.\n",
file->sf_fname);
perror("Write fike footer\n");
}
fd = fileno(file->sf_file);
fsync(fd);
if ((err = fclose(file->sf_file)) != 0)
{
fprintf(stderr,
"* Closing file %s failed due to %d, %s.\n",
file->sf_fname,
errno,
strerror(errno));
}
else
{
ss_dfprintf(stderr, "Closed %s\n", file->sf_fname);
skygw_file_free (file);
}
}
}
/**
* Find the given needle - user-provided literal - and replace it with
* replacement string. Separate user-provided literals from matching table names
* etc. by searching only substrings preceded by non-letter and non-number.
*
* @param haystack Plain text query string, not to be freed
* @param needle Substring to be searched, not to be freed
* @param replacement Replacement text, not to be freed
*
* @return newly allocated string where needle is replaced
*/
char* replace_literal(
char* haystack,
const char* needle,
const char* replacement)
{
const char* prefix = "[ ='\",\\(]"; /*< ' ','=','(',''',''"',',' are allowed before needle */
const char* suffix = "([^[:alnum:]]|$)"; /*< alpha-num chars aren't allowed after the needle */
char* search_re;
char* newstr;
regex_t re;
regmatch_t match;
int rc;
size_t rlen = strlen(replacement);
size_t nlen = strlen(needle);
size_t hlen = strlen(haystack);
search_re = (char *)malloc(strlen(prefix)+nlen+strlen(suffix)+1);
if (search_re == NULL)
{
fprintf(stderr, "Regex memory allocation failed : %s\n",
strerror(errno));
newstr = haystack;
goto retblock;
}
sprintf(search_re, "%s%s%s", prefix, needle, suffix);
/** Allocate memory for new string +1 for terminating byte */
newstr = (char *)malloc(hlen-nlen+rlen+1);
if (newstr == NULL)
{
fprintf(stderr, "Regex memory allocation failed : %s\n",
strerror(errno));
free(search_re);
free(newstr);
newstr = haystack;
goto retblock;
}
rc = regcomp(&re, search_re, REG_EXTENDED|REG_ICASE);
ss_info_dassert(rc == 0, "Regex check");
if (rc != 0)
{
char error_message[MAX_ERROR_MSG];
regerror (rc, &re, error_message, MAX_ERROR_MSG);
fprintf(stderr,
"Regex error compiling '%s': %s\n",
search_re,
error_message);
free(search_re);
free(newstr);
newstr = haystack;
goto retblock;
}
rc = regexec(&re, haystack, 1, &match, 0);
if (rc != 0)
{
free(search_re);
free(newstr);
regfree(&re);
newstr = haystack;
goto retblock;
}
memcpy(newstr, haystack, match.rm_so+1);
memcpy(newstr+match.rm_so+1, replacement, rlen);
/** +1 is terminating byte */
memcpy(newstr+match.rm_so+1+rlen, haystack+match.rm_so+1+nlen, hlen-(match.rm_so+1)-nlen+1);
regfree(&re);
free(haystack);
free(search_re);
retblock:
return newstr;
}
/**
* Calculate the number of decimal numbers from a size_t value.
*
* @param value value
*
* @return number of decimal numbers of which the value consists of
* value==123 returns 3, for example.
* @note Does the same as UINTLEN macro
*/
size_t get_decimal_len(
size_t value)
{
return value > 0 ? (size_t) log10 ((double) value) + 1 : 1;
}
/**
* Check if the provided pathname is POSIX-compliant. The valid characters
* are [a-z A-Z 0-9._-].
* @param path A null-terminated string
* @return true if it is a POSIX-compliant pathname, otherwise false
*/
bool is_valid_posix_path(char* path)
{
char* ptr = path;
while (*ptr != '\0')
{
if (isalnum (*ptr) ||
*ptr == '/' ||
*ptr == '.' ||
*ptr == '-' ||
*ptr == '_')
{
ptr++;
}
else
{
return false;
}
}
return true;
}
/**
* Strip escape characters from a character string.
* @param String to parse.
* @return True if parsing was successful, false on errors.
*/
bool
strip_escape_chars (char* val)
{
int cur, end;
if (val == NULL)
return false;
end = strlen (val) + 1;
cur = 0;
while (cur < end)
{
if (val[cur] == '\\')
{
memmove (val + cur, val + cur + 1,end - cur - 1);
end--;
}
cur++;
}
return true;
}
/**
* Calculate a hash value for a null-terminated string.
* @param key String to hash
* @return Hash value of the string
*/
int simple_str_hash(char* key)
{
if(key == NULL){
return 0;
}
int hash = 0,c = 0;
char* ptr = key;
while((c = *ptr++)){
hash = c + (hash << 6) + (hash << 16) - hash;
}
return hash;
}
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