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#include <pthread.h>
/**
* see sqlite3_csv_vtab-mem.h for background info
*/
#if defined(_WIN32) || defined(_WIN64)
#include <process.h>
#else
#include <unistd.h>
#endif
struct sqlite3_zsv_data {
struct sqlite3_zsv_data *next;
pid_t pid;
char *filename;
struct zsv_opts opts;
struct zsv_prop_handler custom_prop_handler;
};
pthread_mutex_t sqlite3_zsv_data_mutex;
struct sqlite3_zsv_data *sqlite3_zsv_data_g = NULL;
/**
* Our shared memory structure should be locked for read/write
*/
static int sqlite3_zsv_data_lock(void) {
#ifndef NO_THREADING
pthread_mutex_lock(&sqlite3_zsv_data_mutex);
#endif
return 0;
}
static int sqlite3_zsv_data_unlock(void) {
#ifndef NO_THREADING
pthread_mutex_unlock(&sqlite3_zsv_data_mutex);
#endif
return 0;
}
static void sqlite3_zsv_data_delete(struct sqlite3_zsv_data *e) {
if (e) {
free(e->filename);
}
free(e);
}
void sqlite3_zsv_list_delete(void **list) {
for (struct sqlite3_zsv_data *next, *e = *list; e; e = next) {
next = e->next;
sqlite3_zsv_data_delete(e);
}
#ifndef NO_THREADING
pthread_mutex_destroy(&sqlite3_zsv_data_mutex);
#endif
*list = NULL;
}
static struct sqlite3_zsv_data *sqlite3_zsv_data_new(const char *filename, struct zsv_opts *opts,
struct zsv_prop_handler *custom_prop_handler) {
if (!filename)
return NULL;
struct sqlite3_zsv_data *e = calloc(1, sizeof(*e));
if (e) {
e->pid = getpid();
e->filename = strdup(filename);
if (opts)
e->opts = *opts;
if (custom_prop_handler)
e->custom_prop_handler = *custom_prop_handler;
if (e->filename)
return e;
}
sqlite3_zsv_data_delete(e);
return NULL;
}
int sqlite3_zsv_list_add(const char *filename, struct zsv_opts *opts, struct zsv_prop_handler *custom_prop_handler) {
struct sqlite3_zsv_data **list = &sqlite3_zsv_data_g;
struct sqlite3_zsv_data *e = sqlite3_zsv_data_new(filename, opts, custom_prop_handler);
if (e) {
struct sqlite3_zsv_data **next;
if (sqlite3_zsv_data_lock()) {
sqlite3_zsv_data_delete(e);
return -1;
} else {
for (next = list; *next; next = &(*next)->next)
;
*next = e;
sqlite3_zsv_data_unlock();
return 0;
}
}
return ENOMEM;
}
static int sqlite3_zsv_data_cmp(struct sqlite3_zsv_data *x, const char *filename, pid_t pid) {
return strcmp(x->filename, filename) && x->pid == pid;
}
struct sqlite3_zsv_data *sqlite3_zsv_data_find(const char *filename) {
struct sqlite3_zsv_data *list = sqlite3_zsv_data_g;
struct sqlite3_zsv_data *found = NULL;
pid_t pid = getpid();
if (!sqlite3_zsv_data_lock()) {
for (struct sqlite3_zsv_data *e = list; e && !found; e = e->next) {
if (!sqlite3_zsv_data_cmp(e, filename, pid))
found = e;
}
if (sqlite3_zsv_data_unlock())
fprintf(stderr, "Error unlocking sqlite3-csv-zsv shared mem lock\n");
}
return found;
}
int sqlite3_zsv_list_remove(const char *filename) {
if (!filename)
return 0;
struct sqlite3_zsv_data **list = &sqlite3_zsv_data_g;
struct sqlite3_zsv_data *found = NULL;
pid_t pid = getpid();
if (*list) {
if (!sqlite3_zsv_data_cmp(*list, filename, pid)) {
// found a match at the head of list
found = *list;
*list = found->next;
} else {
// look for a match somewhere after the first element
for (struct sqlite3_zsv_data *prior = *list; prior->next != NULL; prior = prior->next) {
if (!sqlite3_zsv_data_cmp(prior->next, filename, pid)) {
found = prior->next;
prior->next = prior->next->next;
break;
}
}
}
}
if (found) {
sqlite3_zsv_data_delete(found);
return 0;
}
return ENOENT; // not found
}
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