Struct odbc_api::handles::OutputStringBuffer

pub struct OutputStringBuffer { /* private fields */ }

We use this as an output buffer for strings. Allows for detecting truncation.

Implementations

impl OutputStringBuffer

pub fn empty() -> Self

Creates an empty string buffer. Useful if you want to e.g. use a prompt to complete the connection string, but are not interessted in the actual completed connection string.

Examples found in repository

src/handles/connection.rs (line 114)

    pub fn connect_with_connection_string(&mut self, connection_string: &SqlText) -> SqlResult<()> {
        unsafe {
            let parent_window = null_mut();
            let mut completed_connection_string = OutputStringBuffer::empty();

            self.driver_connect(
                connection_string,
                parent_window,
                &mut completed_connection_string,
                DriverConnectOption::NoPrompt,
            )
            // Since we did pass NoPrompt we know the user can not abort the prompt.
            .map(|_connection_string_is_complete| ())
        }
    }

pub fn with_buffer_size(max_str_len: usize) -> Self

Creates a new instance of an output string buffer which can hold strings up to a size of max_str_len - 1 characters. `-1 because one place is needed for the terminating zero. To hold a connection string the size should be at least 1024.

Examples found in repository

src/handles/sql_char.rs (line 188)

    pub fn empty() -> Self {
        Self::with_buffer_size(0)
    }

pub fn mut_buf_ptr(&mut self) -> *mut SqlChar

Ptr to the internal buffer. Used by ODBC API calls to fill the buffer.

Examples found in repository

src/handles/connection.rs (line 149)

    pub unsafe fn driver_connect(
        &mut self,
        connection_string: &SqlText,
        parent_window: HWnd,
        completed_connection_string: &mut OutputStringBuffer,
        driver_completion: DriverConnectOption,
    ) -> SqlResult<()> {
        sql_driver_connect(
            self.handle,
            parent_window,
            connection_string.ptr(),
            connection_string.len_char().try_into().unwrap(),
            completed_connection_string.mut_buf_ptr(),
            completed_connection_string.buf_len(),
            completed_connection_string.mut_actual_len_ptr(),
            driver_completion,
        )
        .into_sql_result("SQLDriverConnect")
    }

pub fn buf_len(&self) -> i16

Length of the internal buffer in characters including the terminating zero.

Examples found in repository

src/handles/connection.rs (line 150)

    pub unsafe fn driver_connect(
        &mut self,
        connection_string: &SqlText,
        parent_window: HWnd,
        completed_connection_string: &mut OutputStringBuffer,
        driver_completion: DriverConnectOption,
    ) -> SqlResult<()> {
        sql_driver_connect(
            self.handle,
            parent_window,
            connection_string.ptr(),
            connection_string.len_char().try_into().unwrap(),
            completed_connection_string.mut_buf_ptr(),
            completed_connection_string.buf_len(),
            completed_connection_string.mut_actual_len_ptr(),
            driver_completion,
        )
        .into_sql_result("SQLDriverConnect")
    }

pub fn mut_actual_len_ptr(&mut self) -> *mut i16

Mutable pointer to actual output string length. Used by ODBC API calls to report truncation.

Examples found in repository

src/handles/connection.rs (line 151)

    pub unsafe fn driver_connect(
        &mut self,
        connection_string: &SqlText,
        parent_window: HWnd,
        completed_connection_string: &mut OutputStringBuffer,
        driver_completion: DriverConnectOption,
    ) -> SqlResult<()> {
        sql_driver_connect(
            self.handle,
            parent_window,
            connection_string.ptr(),
            connection_string.len_char().try_into().unwrap(),
            completed_connection_string.mut_buf_ptr(),
            completed_connection_string.buf_len(),
            completed_connection_string.mut_actual_len_ptr(),
            driver_completion,
        )
        .into_sql_result("SQLDriverConnect")
    }

pub fn to_utf8(&self) -> String

Call this method to extract string from buffer after ODBC has filled it.

pub fn is_truncated(&self) -> bool

True if the buffer had not been large enough to hold the string.

Examples found in repository

src/handles/sql_char.rs (line 224)

    pub fn to_utf8(&self) -> String {
        if self.buffer.is_empty() {
            return String::new();
        }

        if self.is_truncated() {
            // If the string is truncated we return the entire buffer excluding the terminating
            // zero.
            slice_to_utf8(&self.buffer[0..(self.buffer.len() - 1)]).unwrap()
        } else {
            // If the string is not truncated, we return not the entire buffer, but only the slice
            // containing the actual string.
            let actual_length: usize = self.actual_length.try_into().unwrap();
            slice_to_utf8(&self.buffer[0..actual_length]).unwrap()
        }
    }