ISAR/rusqlite
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This commit is contained in:
Gwenael Treguier 2015-08-08 16:11:31 +02:00
parent d1f5ce2435
commit 3b830b4bce
1 changed files with 12 additions and 0 deletions
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12
src/blob.rs
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@ -1,15 +1,18 @@
//! incremental BLOB I/O
use std::mem; use std::mem;
use std::ptr; use std::ptr;
use super::ffi; use super::ffi;
use {SqliteError, SqliteResult, SqliteConnection}; use {SqliteError, SqliteResult, SqliteConnection};
/// Handle to an open BLOB
pub struct SqliteBlob<'conn> { pub struct SqliteBlob<'conn> {
conn: &'conn SqliteConnection, conn: &'conn SqliteConnection,
blob: *mut ffi::sqlite3_blob, blob: *mut ffi::sqlite3_blob,
pos: i32, pos: i32,
} }
/// Enumeration of possible methods to seek within an BLOB.
pub enum SeekFrom { pub enum SeekFrom {
Start(i32), Start(i32),
End(i32), End(i32),
@ -17,6 +20,7 @@ pub enum SeekFrom {
} }
impl SqliteConnection { impl SqliteConnection {
/// Open a handle to the BLOB located in `row`, `column`, `table` in database `db` ('main', 'temp', ...)
pub fn blob_open<'a>(&'a self, db: &str, table: &str, column: &str, row: i64, read_only: bool) -> SqliteResult<SqliteBlob<'a>> { pub fn blob_open<'a>(&'a self, db: &str, table: &str, column: &str, row: i64, read_only: bool) -> SqliteResult<SqliteBlob<'a>> {
let mut c = self.db.borrow_mut(); let mut c = self.db.borrow_mut();
let mut blob = ptr::null_mut(); let mut blob = ptr::null_mut();
@ -31,6 +35,7 @@ impl SqliteConnection {
} }
impl<'conn> SqliteBlob<'conn> { impl<'conn> SqliteBlob<'conn> {
/// Move a BLOB handle to a new row
pub fn reopen(&mut self, row: i64) -> SqliteResult<()> { pub fn reopen(&mut self, row: i64) -> SqliteResult<()> {
let rc = unsafe{ ffi::sqlite3_blob_reopen(self.blob, row) }; let rc = unsafe{ ffi::sqlite3_blob_reopen(self.blob, row) };
if rc != ffi::SQLITE_OK { if rc != ffi::SQLITE_OK {
@ -40,10 +45,12 @@ impl<'conn> SqliteBlob<'conn> {
Ok(()) Ok(())
} }
/// Return the size in bytes of the BLOB
pub fn size(&self) -> i32 { pub fn size(&self) -> i32 {
unsafe{ ffi::sqlite3_blob_bytes(self.blob) } unsafe{ ffi::sqlite3_blob_bytes(self.blob) }
} }
/// Read data from a BLOB incrementally
pub fn read(&mut self, buf: &mut [u8]) -> SqliteResult<i32> { pub fn read(&mut self, buf: &mut [u8]) -> SqliteResult<i32> {
if buf.len() > ::std::i32::MAX as usize { if buf.len() > ::std::i32::MAX as usize {
return Err(SqliteError { return Err(SqliteError {
@ -66,6 +73,9 @@ impl<'conn> SqliteBlob<'conn> {
}) })
} }
/// Write data into a BLOB incrementally
///
/// This function may only modify the contents of the BLOB; it is not possible to increase the size of a BLOB using this API.
pub fn write(&mut self, buf: &[u8]) -> SqliteResult<i32> { pub fn write(&mut self, buf: &[u8]) -> SqliteResult<i32> {
if buf.len() > ::std::i32::MAX as usize { if buf.len() > ::std::i32::MAX as usize {
return Err(SqliteError { return Err(SqliteError {
@ -88,6 +98,7 @@ impl<'conn> SqliteBlob<'conn> {
}) })
} }
/// Seek to an offset, in bytes, in BLOB.
pub fn seek(&mut self, pos: SeekFrom) { pub fn seek(&mut self, pos: SeekFrom) {
self.pos = match pos { self.pos = match pos {
SeekFrom::Start(offset) => offset, SeekFrom::Start(offset) => offset,
@ -96,6 +107,7 @@ impl<'conn> SqliteBlob<'conn> {
}; };
} }
/// Close a BLOB handle
pub fn close(mut self) -> SqliteResult<()> { pub fn close(mut self) -> SqliteResult<()> {
self.close_() self.close_()
} }