1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
// This file was generated by gir (https://github.com/gtk-rs/gir)
// from gir-files (https://github.com/gtk-rs/gir-files)
// DO NOT EDIT

use crate::{Initable, MemoryMonitorWarningLevel};
use glib::{
    prelude::*,
    signal::{connect_raw, SignalHandlerId},
    translate::*,
};
use std::{boxed::Box as Box_, fmt, mem::transmute};

glib::wrapper! {
    /// [`MemoryMonitor`][crate::MemoryMonitor] will monitor system memory and suggest to the application
    /// when to free memory so as to leave more room for other applications.
    /// It is implemented on Linux using the [Low Memory Monitor](https://gitlab.freedesktop.org/hadess/low-memory-monitor/)
    /// ([API documentation](https://hadess.pages.freedesktop.org/low-memory-monitor/)).
    ///
    /// There is also an implementation for use inside Flatpak sandboxes.
    ///
    /// Possible actions to take when the signal is received are:
    ///
    ///  - Free caches
    ///  - Save files that haven't been looked at in a while to disk, ready to be reopened when needed
    ///  - Run a garbage collection cycle
    ///  - Try and compress fragmented allocations
    ///  - Exit on idle if the process has no reason to stay around
    ///  - Call [`malloc_trim(3)`](man:malloc_trim) to return cached heap pages to
    ///  the kernel (if supported by your libc)
    ///
    /// Note that some actions may not always improve system performance, and so
    /// should be profiled for your application. ``malloc_trim()``, for example, may
    /// make future heap allocations slower (due to releasing cached heap pages back
    /// to the kernel).
    ///
    /// See [`MemoryMonitorWarningLevel`][crate::MemoryMonitorWarningLevel] for details on the various warning levels.
    ///
    ///
    ///
    /// **⚠️ The following code is in C ⚠️**
    ///
    /// ```C
    /// static void
    /// warning_cb (GMemoryMonitor *m, GMemoryMonitorWarningLevel level)
    /// {
    ///   g_debug ("Warning level: %d", level);
    ///   if (warning_level > G_MEMORY_MONITOR_WARNING_LEVEL_LOW)
    ///     drop_caches ();
    /// }
    ///
    /// static GMemoryMonitor *
    /// monitor_low_memory (void)
    /// {
    ///   GMemoryMonitor *m;
    ///   m = g_memory_monitor_dup_default ();
    ///   g_signal_connect (G_OBJECT (m), "low-memory-warning",
    ///                     G_CALLBACK (warning_cb), NULL);
    ///   return m;
    /// }
    /// ```
    ///
    /// Don't forget to disconnect the [`low-memory-warning`][struct@crate::MemoryMonitor#low-memory-warning]
    /// signal, and unref the [`MemoryMonitor`][crate::MemoryMonitor] itself when exiting.
    ///
    /// ## Signals
    ///
    ///
    /// #### `low-memory-warning`
    ///  Emitted when the system is running low on free memory. The signal
    /// handler should then take the appropriate action depending on the
    /// warning level. See the [`MemoryMonitorWarningLevel`][crate::MemoryMonitorWarningLevel] documentation for
    /// details.
    ///
    ///
    ///
    /// # Implements
    ///
    /// [`MemoryMonitorExt`][trait@crate::prelude::MemoryMonitorExt], [`InitableExt`][trait@crate::prelude::InitableExt]
    #[doc(alias = "GMemoryMonitor")]
    pub struct MemoryMonitor(Interface<ffi::GMemoryMonitor, ffi::GMemoryMonitorInterface>) @requires Initable;

    match fn {
        type_ => || ffi::g_memory_monitor_get_type(),
    }
}

impl MemoryMonitor {
    pub const NONE: Option<&'static MemoryMonitor> = None;

    /// Gets a reference to the default [`MemoryMonitor`][crate::MemoryMonitor] for the system.
    ///
    /// # Returns
    ///
    /// a new reference to the default [`MemoryMonitor`][crate::MemoryMonitor]
    #[doc(alias = "g_memory_monitor_dup_default")]
    pub fn dup_default() -> MemoryMonitor {
        unsafe { from_glib_full(ffi::g_memory_monitor_dup_default()) }
    }
}

mod sealed {
    pub trait Sealed {}
    impl<T: super::IsA<super::MemoryMonitor>> Sealed for T {}
}

/// Trait containing all [`struct@MemoryMonitor`] methods.
///
/// # Implementors
///
/// [`MemoryMonitor`][struct@crate::MemoryMonitor]
pub trait MemoryMonitorExt: IsA<MemoryMonitor> + sealed::Sealed + 'static {
    /// Emitted when the system is running low on free memory. The signal
    /// handler should then take the appropriate action depending on the
    /// warning level. See the [`MemoryMonitorWarningLevel`][crate::MemoryMonitorWarningLevel] documentation for
    /// details.
    /// ## `level`
    /// the [`MemoryMonitorWarningLevel`][crate::MemoryMonitorWarningLevel] warning level
    #[cfg(feature = "v2_64")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v2_64")))]
    #[doc(alias = "low-memory-warning")]
    fn connect_low_memory_warning<F: Fn(&Self, MemoryMonitorWarningLevel) + 'static>(
        &self,
        f: F,
    ) -> SignalHandlerId {
        unsafe extern "C" fn low_memory_warning_trampoline<
            P: IsA<MemoryMonitor>,
            F: Fn(&P, MemoryMonitorWarningLevel) + 'static,
        >(
            this: *mut ffi::GMemoryMonitor,
            level: ffi::GMemoryMonitorWarningLevel,
            f: glib::ffi::gpointer,
        ) {
            let f: &F = &*(f as *const F);
            f(
                MemoryMonitor::from_glib_borrow(this).unsafe_cast_ref(),
                from_glib(level),
            )
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                b"low-memory-warning\0".as_ptr() as *const _,
                Some(transmute::<_, unsafe extern "C" fn()>(
                    low_memory_warning_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }
}

impl<O: IsA<MemoryMonitor>> MemoryMonitorExt for O {}

impl fmt::Display for MemoryMonitor {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.write_str("MemoryMonitor")
    }
}