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#ifndef LIGHTNING_WALLET_DB_COMMON_H
#define LIGHTNING_WALLET_DB_COMMON_H
#include "config.h"
#include <ccan/autodata/autodata.h>
#include <ccan/list/list.h>
#include <ccan/short_types/short_types.h>
#include <sqlite3.h>
#include <stdbool.h>
/* For testing, we want to catch fatal messages. */
#ifndef db_fatal
#define db_fatal fatal
#endif
struct db {
char *filename;
const char *in_transaction;
/* DB-specific context */
void *conn;
/* The configuration, including translated queries for the current
* instance. */
const struct db_config *config;
const char **changes;
/* List of statements that have been created but not executed yet. */
struct list_head pending_statements;
char *error;
};
struct db_query {
const char *name;
const char *query;
/* How many placeholders are in the query (and how many will we have
to allocate when instantiating this query)? */
size_t placeholders;
/* Is this a read-only query? If it is there's no need to tell plugins
* about it. */
bool readonly;
};
enum db_binding_type {
DB_BINDING_UNINITIALIZED = 0,
DB_BINDING_NULL,
DB_BINDING_BLOB,
DB_BINDING_TEXT,
DB_BINDING_UINT64,
DB_BINDING_INT,
};
struct db_binding {
enum db_binding_type type;
union {
s32 i;
u64 u64;
const char* text;
const u8 *blob;
} v;
size_t len;
};
struct db_stmt {
/* Our entry in the list of pending statements. */
struct list_node list;
/* Database we are querying */
struct db *db;
/* Which SQL statement are we trying to execute? */
struct db_query *query;
/* Which parameters are we binding to the statement? */
struct db_binding *bindings;
/* Where are we calling this statement from? */
const char *location;
const char *error;
/* Pointer to DB-specific statement. */
void *inner_stmt;
bool executed;
int row;
};
struct db_config {
const char *name;
struct db_query *queries;
size_t num_queries;
/* Function used to execute a statement that doesn't result in a
* response. */
bool (*exec_fn)(struct db_stmt *stmt);
/* Function to execute a query that will result in a response. */
bool (*query_fn)(struct db_stmt *stmt);
/* Function used to step forwards through query results. Returns
* `false` if there are no more rows to return. */
bool (*step_fn)(struct db_stmt *stmt);
bool (*begin_tx_fn)(struct db *db);
bool (*commit_tx_fn)(struct db *db);
/* The free function must make sure that any associated state stored
* in `stmt->inner_stmt` is freed correctly, setting the pointer to
* NULL after cleaning up. It will ultmately be called by the
* destructor of `struct db_stmt`, before clearing the db_stmt
* itself. */
void (*stmt_free_fn)(struct db_stmt *db_stmt);
/* Column access in a row. Only covers the primitives, others need to
* use these internally to translate (hence the non-allocating
* column_{text,blob}_fn since most other types want in place
* assignment. */
bool (*column_is_null_fn)(struct db_stmt *stmt, int col);
u64 (*column_u64_fn)(struct db_stmt *stmt, int col);
size_t (*column_bytes_fn)(struct db_stmt *stmt, int col);
const void *(*column_blob_fn)(struct db_stmt *stmt, int col);
const unsigned char *(*column_text_fn)(struct db_stmt *stmt, int col);
s64 (*column_int_fn)(struct db_stmt *stmt, int col);
u64 (*last_insert_id_fn)(struct db_stmt *stmt);
size_t (*count_changes_fn)(struct db_stmt *stmt);
bool (*setup_fn)(struct db *db);
void (*teardown_fn)(struct db *db);
};
/* Provide a way for DB backends to register themselves */
AUTODATA_TYPE(db_backends, struct db_config);
/**
* Report a statement that changes the wallet
*
* Allows the DB driver to report an expanded statement during
* execution. Changes are queued up and reported to the `db_write` plugin hook
* upon committing.
*/
void db_changes_add(struct db_stmt *db_stmt, const char * expanded);
#endif /* LIGHTNING_WALLET_DB_COMMON_H */