diesel/mysql/connection/stmt/
metadata.rs

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1#![allow(unsafe_code)] // module uses ffi
2use std::ffi::CStr;
3use std::ptr::NonNull;
4use std::slice;
5
6use super::ffi;
7use crate::mysql::connection::bind::Flags;
8
9pub(in crate::mysql::connection) struct StatementMetadata {
10    result: NonNull<ffi::MYSQL_RES>,
11}
12
13impl StatementMetadata {
14    pub(in crate::mysql::connection) fn new(result: NonNull<ffi::MYSQL_RES>) -> Self {
15        StatementMetadata { result }
16    }
17
18    pub(in crate::mysql::connection) fn fields(&'_ self) -> &'_ [MysqlFieldMetadata<'_>] {
19        unsafe {
20            let num_fields = ffi::mysql_num_fields(self.result.as_ptr());
21            let field_ptr = ffi::mysql_fetch_fields(self.result.as_ptr());
22            if field_ptr.is_null() {
23                &[]
24            } else {
25                slice::from_raw_parts(field_ptr as _, num_fields as usize)
26            }
27        }
28    }
29}
30
31impl Drop for StatementMetadata {
32    fn drop(&mut self) {
33        unsafe { ffi::mysql_free_result(self.result.as_mut()) };
34    }
35}
36
37#[repr(transparent)]
38pub(in crate::mysql::connection) struct MysqlFieldMetadata<'a>(
39    ffi::MYSQL_FIELD,
40    std::marker::PhantomData<&'a ()>,
41);
42
43impl MysqlFieldMetadata<'_> {
44    pub(in crate::mysql::connection) fn field_name(&self) -> Option<&str> {
45        if self.0.name.is_null() {
46            None
47        } else {
48            unsafe {
49                Some(CStr::from_ptr(self.0.name).to_str().expect(
50                    "Expect mysql field names to be UTF-8, because we \
51                     requested UTF-8 encoding on connection setup",
52                ))
53            }
54        }
55    }
56
57    pub(in crate::mysql::connection) fn field_type(&self) -> ffi::enum_field_types {
58        self.0.type_
59    }
60
61    pub(in crate::mysql::connection) fn flags(&self) -> Flags {
62        Flags::from(self.0.flags)
63    }
64}
diesel/mysql/connection/stmt/metadata.rs

diesel/mysql/connection/stmt/
metadata.rs
