candding 0.1.0

Pure candle embeddings for Rust with no ONNX: dense, sparse, multi-vector and rerank models today, image models on the roadmap
Documentation 
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

//! Compute device selection.

mod memory;

use candle_core::Device;
use candle_core::utils::cuda_is_available;
use candle_core::utils::metal_is_available;
pub(crate) use memory::budget_bytes;

use crate::error::CanddingError;
use crate::error::Result;
use crate::registry::Backend;

/// Metal first, then CUDA, then CPU, depending on compiled features.
pub fn auto() -> Result<Device> {
  if metal_is_available() {
    return metal(0);
  }
  if cuda_is_available() {
    return cuda(0);
  }
  Ok(Device::Cpu)
}

pub fn cpu() -> Device {
  Device::Cpu
}

pub fn metal(ordinal: usize) -> Result<Device> {
  Device::new_metal(ordinal).map_err(|e| device_error(Backend::Metal, e))
}

pub fn cuda(ordinal: usize) -> Result<Device> {
  Device::new_cuda(ordinal).map_err(|e| device_error(Backend::Cuda, e))
}

/// candle's refusal of a backend its build left out, as `BackendNotCompiled`; any other failure keeps its message.
fn device_error(backend: Backend, error: candle_core::Error) -> CanddingError {
  match error {
    candle_core::Error::NotCompiledWithMetalSupport
    | candle_core::Error::NotCompiledWithCudaSupport => {
      CanddingError::BackendNotCompiled { backend }
    }
    error => CanddingError::Device {
      backend,
      reason: error.to_string(),
    },
  }
}

/// Short backend name used in errors and the CLI.
pub fn describe(device: &Device) -> &'static str {
  match device {
    Device::Cpu => "cpu",
    Device::Metal(_) => "metal",
    Device::Cuda(_) => "cuda",
  }
}

#[cfg(test)]
mod tests {
  use super::*;

  #[test]
  fn auto_matches_compiled_features() {
    let device = auto().unwrap();
    let expected = if cfg!(feature = "metal") {
      "metal"
    } else if cfg!(feature = "cuda") {
      "cuda"
    } else {
      "cpu"
    };
    assert_eq!(describe(&device), expected);
  }

  #[test]
  fn cpu_is_cpu() {
    assert_eq!(describe(&cpu()), "cpu");
  }

  #[test]
  fn a_backend_left_out_of_the_build_is_refused_as_not_compiled() {
    if !cfg!(feature = "metal") {
      assert!(
        matches!(
          metal(0),
          Err(CanddingError::BackendNotCompiled {
            backend: Backend::Metal
          })
        ),
        "{:?}",
        metal(0).err()
      );
    }
    if !cfg!(feature = "cuda") {
      assert!(
        matches!(
          cuda(0),
          Err(CanddingError::BackendNotCompiled {
            backend: Backend::Cuda
          })
        ),
        "{:?}",
        cuda(0).err()
      );
    }
  }

  #[test]
  fn any_other_device_failure_keeps_the_backend_and_candles_message() {
    let error = device_error(
      Backend::Cuda,
      candle_core::Error::Msg("no device 3".to_string()),
    );
    assert!(
      matches!(&error, CanddingError::Device { backend: Backend::Cuda, reason } if reason == "no device 3"),
      "{error:?}"
    );
    let left_out = device_error(
      Backend::Metal,
      candle_core::Error::NotCompiledWithMetalSupport,
    );
    assert!(
      matches!(
        left_out,
        CanddingError::BackendNotCompiled {
          backend: Backend::Metal
        }
      ),
      "{left_out:?}"
    );
  }
}