Merge #864

864: Remove `power` module r=kvark a=GabrielMajeri

**Connections**
Closes #859 

**Description**
Removes the `power.rs` module. If the user wants to detect the battery status and choose between low-power and high-performance, they can do so themselves.

**Testing**
Tested with core.

Co-authored-by: Gabriel Majeri <gabriel.majeri6@gmail.com>

wgpu-core/src/instance.rs

@@ -7,7 +7,7 @@ use crate::{
     device::Device,
     hub::{GfxBackend, Global, GlobalIdentityHandlerFactory, Input, Token},
     id::{AdapterId, DeviceId, SurfaceId, Valid},
-    power, span, LifeGuard, PrivateFeatures, Stored, MAX_BIND_GROUPS,
+    span, LifeGuard, PrivateFeatures, Stored, MAX_BIND_GROUPS,
 };
 
 use wgt::{Backend, BackendBit, DeviceDescriptor, PowerPreference, BIND_BUFFER_ALIGNMENT};
@@ -500,18 +500,9 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         }
 
         let preferred_gpu = match desc.power_preference {
-            PowerPreference::Default => match power::is_battery_discharging() {
-                Ok(false) => discrete.or(integrated).or(other).or(virt),
-                Ok(true) => integrated.or(discrete).or(other).or(virt),
-                Err(err) => {
-                    tracing::debug!(
-                        "Power info unavailable, preferring integrated gpu ({})",
-                        err
-                    );
-                    integrated.or(discrete).or(other).or(virt)
-                }
-            },
-            PowerPreference::LowPower => integrated.or(other).or(discrete).or(virt),
+            PowerPreference::Default | PowerPreference::LowPower => {
+                integrated.or(other).or(discrete).or(virt)
+            }
             PowerPreference::HighPerformance => discrete.or(other).or(integrated).or(virt),
         };
 

wgpu-core/src/lib.rs

@@ -37,7 +37,6 @@ pub mod id;
 pub mod instance;
 pub mod logging;
 pub mod pipeline;
-pub mod power;
 pub mod resource;
 pub mod swap_chain;
 mod track;

wgpu-core/src/power.rs

@@ -1,66 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-use thiserror::Error;
-
-#[derive(Debug, Error)]
-pub enum Error {
-    #[error("battery status is unsupported on this platform")]
-    Unsupported,
-    #[error("battery status retrieval failed: {0}")]
-    Error(Box<dyn std::error::Error>),
-}
-
-#[cfg(all(
-    feature = "battery",
-    any(
-        target_os = "linux",
-        target_os = "macos",
-        target_os = "windows",
-        target_os = "dragonfly",
-        target_os = "freebsd"
-    )
-))]
-mod platform {
-    use super::Error;
-    use battery::{self, Manager, State};
-
-    impl From<battery::errors::Error> for Error {
-        fn from(err: battery::errors::Error) -> Error {
-            // Box the error so that the battery::errors::Error type does
-            // not leak out of this module.
-            Error::Error(Box::new(err))
-        }
-    }
-
-    pub fn is_battery_discharging() -> Result<bool, Error> {
-        let manager = Manager::new()?;
-        for battery in manager.batteries()? {
-            if battery?.state() == State::Discharging {
-                return Ok(true);
-            }
-        }
-        Ok(false)
-    }
-}
-
-#[cfg(any(
-    not(feature = "battery"),
-    not(any(
-        target_os = "linux",
-        target_os = "macos",
-        target_os = "windows",
-        target_os = "dragonfly",
-        target_os = "freebsd"
-    ))
-))]
-mod platform {
-    use super::Error;
-
-    pub fn is_battery_discharging() -> Result<bool, Error> {
-        Err(Error::Unsupported)
-    }
-}
-
-pub use platform::is_battery_discharging;