bson_visitor_t (3) Linux Manual Page
NAME
bson_visitor_t – The bson_visitor_t structure provides a series of callbacks that can be called while iterating a BSON document. This may simplify the conversion of a bson_t to a higher level language structure.
SYNOPSIS
#include <bson.h>
typedef struct
{
bool (*visit_before)(const bson_iter_t *iter,
const char *key,
void *data);
bool (*visit_after)(const bson_iter_t *iter,
const char *key,
void *data);
void (*visit_corrupt)(const bson_iter_t *iter,
void *data);
bool (*visit_double)(const bson_iter_t *iter,
const char *key,
double v_double,
void *data);
bool (*visit_utf8)(const bson_iter_t *iter,
const char *key,
size_t v_utf8_len,
const char *v_utf8,
void *data);
bool (*visit_document)(const bson_iter_t *iter,
const char *key,
const bson_t *v_document,
void *data);
bool (*visit_array)(const bson_iter_t *iter,
const char *key,
const bson_t *v_array,
void *data);
bool (*visit_binary)(const bson_iter_t *iter,
const char *key,
bson_subtype_t v_subtype,
size_t v_binary_len,
const uint8_t *v_binary,
void *data);
bool (*visit_undefined)(const bson_iter_t *iter,
const char *key,
void *data);
bool (*visit_oid)(const bson_iter_t *iter,
const char *key,
const bson_oid_t *v_oid,
void *data);
bool (*visit_bool)(const bson_iter_t *iter,
const char *key,
bool v_bool,
void *data);
bool (*visit_date_time)(const bson_iter_t *iter,
const char *key,
int64_t msec_since_epoch,
void *data);
bool (*visit_null)(const bson_iter_t *iter,
const char *key,
void *data);
bool (*visit_regex)(const bson_iter_t *iter,
const char *key,
const char *v_regex,
const char *v_options,
void *data);
bool (*visit_dbpointer)(const bson_iter_t *iter,
const char *key,
size_t v_collection_len,
const char *v_collection,
const bson_oid_t *v_oid,
void *data);
bool (*visit_code)(const bson_iter_t *iter,
const char *key,
size_t v_code_len,
const char *v_code,
void *data);
bool (*visit_symbol)(const bson_iter_t *iter,
const char *key,
size_t v_symbol_len,
const char *v_symbol,
void *data);
bool (*visit_codewscope)(const bson_iter_t *iter,
const char *key,
size_t v_code_len,
const char *v_code,
const bson_t *v_scope,
void *data);
bool (*visit_int32)(const bson_iter_t *iter,
const char *key,
int32_t v_int32,
void *data);
bool (*visit_timestamp)(const bson_iter_t *iter,
const char *key,
uint32_t v_timestamp,
uint32_t v_increment,
void *data);
bool (*visit_int64)(const bson_iter_t *iter,
const char *key,
int64_t v_int64,
void *data);
bool (*visit_maxkey)(const bson_iter_t *iter,
const char *key,
void *data);
bool (*visit_minkey)(const bson_iter_t *iter,
const char *key,
void *data);
void *padding[9];
} bson_visitor_t;
DESCRIPTION
The bson_visitor_t structure provides a series of callbacks that can be called while iterating a BSON document. This may simplify the conversion of a bson_t to a higher level language structure.
EXAMPLE
#include <bson.h>
#include <stdio.h>
static bool
my_visit_before(const bson_iter_t *iter,
const char *key,
void *data)
{
int *count = (int *)data;
(*count)++;
/* returning true stops further iteration of the document */
return false;
}
static void
count_fields(bson_t *doc)
{
bson_visitor_t visitor;
bson_iter_t iter;
int count = 0;
visitor.visit_before = my_visit_before;
if (bson_iter_init(&iter, doc)) {
bson_iter_visit_all(&iter, &visitor, &count);
}
printf("Found %d fields.
", count);
}
COLOPHON
This page is part of libbson. Please report any bugs at https://jira.mongodb.org/browse/CDRIVER.