mirror of
https://github.com/isar/rusqlite.git
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Virtual Table: WIP
This commit is contained in:
gwenn
parent
0d317d2e23
commit
5b62e2dd5f
@ -18,6 +18,7 @@ backup = []
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blob = []
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functions = []
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trace = []
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vtab = []
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[dependencies]
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time = "~0.1.0"
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@ -89,6 +89,7 @@ mod error;
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#[cfg(feature = "backup")]pub mod backup;
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#[cfg(feature = "functions")] pub mod functions;
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#[cfg(feature = "blob")] pub mod blob;
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#[cfg(feature = "vtab")] pub mod vtab;
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/// Old name for `Result`. `SqliteResult` is deprecated.
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pub type SqliteResult<T> = Result<T>;
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275
src/vtab.rs
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275
src/vtab.rs
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@ -0,0 +1,275 @@
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//! Create virtual tables.
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//! (See http://sqlite.org/vtab.html)
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use std::mem;
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use std::ptr;
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use libc::c_void;
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use {Connection, Result, InnerConnection, str_to_cstring};
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use functions::ToResult;
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use ffi;
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/// Virtual table module.
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/// (See http://sqlite.org/c3ref/module.html)
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// (partial/minimal implementation)
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pub trait Module: Drop {
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type V: VTab;
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/// http://sqlite.org/vtab.html#xconnect
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fn connect(conn: &Connection, args: &[&str]) -> Result<Self::V>; // xcreate() == xconnect()
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// drop() = destroy (http://sqlite.org/c3ref/create_module.html)
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}
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/// VTab describes a particular instance of a virtual table.
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/// (See http://sqlite.org/c3ref/vtab.html)
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// (partial/minimal implementation)
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pub trait VTab: Drop {
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type C: Cursor;
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/// http://sqlite.org/vtab.html#xopen
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fn open(&self) -> Result<Self::C>;
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/// http://sqlite.org/vtab.html#xbestindex
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fn best_index(&self) -> Result<()> {
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// TODO sqlite3_index_info*
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Ok(())
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}
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// drop() = xdisconnect == xDestroy (http://sqlite.org/vtab.html#xdisconnect)
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}
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/// Cursor that points into the virtual table and is used to loop through the virtual table.
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/// (See http://sqlite.org/c3ref/vtab_cursor.html)
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pub trait Cursor: Drop {
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/// http://sqlite.org/vtab.html#xfilter
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fn filter(&self) -> Result<()>; // TODO int idxNum, const char *idxStr, int argc, sqlite3_value **argv
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/// http://sqlite.org/vtab.html#xnext
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fn next(&self) -> Result<()>;
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/// http://sqlite.org/vtab.html#xeof
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fn eof(&self) -> bool;
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/// http://sqlite.org/vtab.html#xcolumn
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fn column<T: ToResult + Sized>(&self, col: i32) -> Result<T>;
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/// http://sqlite.org/vtab.html#xrowid
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fn rowid(&self) -> i64; // TODO vs Result<i64>
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// drop() == http://sqlite.org/vtab.html#xclose
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}
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impl Connection {
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/// Register a virtual table implementation.
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pub fn create_module<M>(&self, module_name: &str, module: M) -> Result<()>
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where M: Module
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{
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self.db
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.borrow_mut()
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.create_module(module_name, module)
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}
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/// Declare the schema of a virtual table.
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pub fn declare_vtab(&self, sql: &str) -> Result<()> {
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self.db
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.borrow_mut()
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.declare_vtab(sql)
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}
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}
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// FIXME copy/paste from function.rs
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unsafe extern "C" fn free_boxed_value<T>(p: *mut libc::c_void) {
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let _: Box<T> = Box::from_raw(mem::transmute(p));
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}
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static RUST_MODULE: ffi::sqlite3_module = ffi::sqlite3_module {
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iVersion: 1,
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xCreate: Some(xCreate),
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xConnect: Some(xCreate), /* A virtual table is eponymous if its xCreate method is the exact same function as the xConnect method */
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xBestIndex: Some(xBestIndex),
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xDisconnect: Some(xDestroy),
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xDestroy: Some(xDestroy),
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xOpen: Some(xOpen),
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xClose: Some(xClose),
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xFilter: Some(xFilter),
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xNext: Some(xNext),
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xEof: Some(xEof),
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xColumn: Some(xColumn),
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xRowid: Some(xRowid),
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xUpdate: None, // TODO
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xBegin: None,
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xSync: None,
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xCommit: None,
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xRollback: None,
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xFindFunction: None,
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xRename: None,
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xSavepoint: None,
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xRelease: None,
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xRollbackTo: None,
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};
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unsafe extern "C" fn xCreate(arg1: *mut ffi::sqlite3,
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pAux: *mut libc::c_void,
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argc: libc::c_int,
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argv: *const *const libc::c_char,
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ppVTab: *mut *mut ffi::sqlite3_vtab,
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arg2: *mut *mut libc::c_char)
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-> libc::c_int {
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unimplemented!()
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}
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unsafe extern "C" fn xBestIndex(pVTab: *mut ffi::sqlite3_vtab,
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info: *mut ffi::sqlite3_index_info)
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-> libc::c_int {
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unimplemented!()
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}
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unsafe extern "C" fn xDestroy(pVTab: *mut ffi::sqlite3_vtab) -> libc::c_int {
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unimplemented!()
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}
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unsafe extern "C" fn xOpen(pVTab: *mut ffi::sqlite3_vtab,
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ppCursor: *mut *mut ffi::sqlite3_vtab_cursor)
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-> libc::c_int {
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unimplemented!()
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}
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unsafe extern "C" fn xClose(cursor: *mut ffi::sqlite3_vtab_cursor) -> libc::c_int {
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unimplemented!()
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}
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unsafe extern "C" fn xFilter(cursor: *mut ffi::sqlite3_vtab_cursor,
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idxNum: libc::c_int,
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idxStr: *const libc::c_char,
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argc: libc::c_int,
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argv: *mut *mut ffi::sqlite3_value)
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-> libc::c_int {
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unimplemented!()
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}
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unsafe extern "C" fn xNext(cursor: *mut ffi::sqlite3_vtab_cursor) -> libc::c_int {
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unimplemented!()
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}
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unsafe extern "C" fn xEof(cursor: *mut ffi::sqlite3_vtab_cursor) -> libc::c_int {
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unimplemented!()
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}
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unsafe extern "C" fn xColumn(cursor: *mut ffi::sqlite3_vtab_cursor,
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ctx: *mut ffi::sqlite3_context,
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i: libc::c_int)
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-> libc::c_int {
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unimplemented!()
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}
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unsafe extern "C" fn xRowid(cursor: *mut ffi::sqlite3_vtab_cursor,
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pRowid: *mut ffi::sqlite3_int64)
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-> libc::c_int {
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unimplemented!()
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}
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unsafe extern "C" fn set_err_msg(cursor: *mut ffi::sqlite3_vtab_cursor,
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err_msg: *mut libc::c_char)
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-> libc::c_int {
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let pVtab = (*cursor).pVtab;
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if !(*pVtab).zErrMsg.is_null() {
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ffi::sqlite3_free((*pVtab).zErrMsg as *mut libc::c_void)
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}
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(*pVtab).zErrMsg = err_msg;
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return ffi::SQLITE_ERROR;
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}
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impl InnerConnection {
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fn create_module<M>(&mut self, module_name: &str, module: M) -> Result<()>
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where M: Module
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{
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let boxed_mod: *mut M = Box::into_raw(Box::new(module));
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let c_name = try!(str_to_cstring(module_name));
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let r = unsafe {
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ffi::sqlite3_create_module_v2(self.db(),
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c_name.as_ptr(),
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ptr::null_mut(), // FIXME *const sqlite3_module
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mem::transmute(boxed_mod),
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Some(mem::transmute(free_boxed_value::<M>)))
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};
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self.decode_result(r)
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}
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fn declare_vtab(&mut self, sql: &str) -> Result<()> {
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let c_sql = try!(str_to_cstring(sql));
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let r = unsafe { ffi::sqlite3_declare_vtab(self.db(), c_sql.as_ptr()) };
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self.decode_result(r)
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}
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}
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// A intarray table
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// #[repr(C)]
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// struct IntArrayVTab {
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// Base class
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// base: ffi::sqlite3_vtab,
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// }
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//
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// impl VTab for IntArrayVTab {
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//
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// }
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//
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// impl Drop for IntArrayVTab {
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// fn drop(&mut self) {
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// FIXME
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// }
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// }
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//
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// A intarray cursor
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// #[repr(C)]
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// struct IntArrayCursor {
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// Base class
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// base: ffi::sqlite3_vtab_cursor,
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// i: usize
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// }
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//
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// impl Cursor for IntArrayCursor {
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// type V = IntArrayVTab;
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//
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// fn filter(&mut self) -> Result<()> {
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// self.i = 0;
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// Ok(())
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// }
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// fn next(&mut self) -> Result<()> {
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// self.i = self.i + 1;
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// Ok(())
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// }
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// fn eof(&self) -> bool {
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// false // FIXME
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// }
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// fn column(&self, ctx: *mut ffi::sqlite3_context, _: i32) -> Result<()> {
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// let v: i64 = 0; // FIXME
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// unsafe {
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// v.set_result(ctx);
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// }
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// Ok(())
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// }
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// fn rowid(&self) -> i64 {
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// self.i as i64
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// }
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// }
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//
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// impl Drop for IntArrayCursor {
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// fn drop(&mut self) {
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// FIXME
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// }
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// }
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// #[repr(C)]
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// #[derive(Copy)]
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// pub struct Struct_sqlite3_vtab {
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// pub pModule: *const sqlite3_module,
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// pub nRef: libc::c_int,
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// pub zErrMsg: *mut libc::c_char,
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// }
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// #[repr(C)]
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// #[derive(Copy)]
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// pub struct Struct_sqlite3_vtab_cursor {
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// pub pVtab: *mut sqlite3_vtab,
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// }
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//
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// file:///usr/local/share/doc/rust/html/book/ffi.html#targeting-callbacks-to-rust-objects
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//
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// #[repr(C)]
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// struct RustObject {
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// a: i32,
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// other members
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// }
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//
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// file:///usr/local/share/doc/rust/html/book/associated-types.html#implementing-associated-types
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// file:///usr/local/share/doc/rust/html/book/closures.html
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//
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#[cfg(test)]
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mod test {
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}
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