github.com/Prakhar-Agarwal-byte/moby@v0.0.0-20231027092010-a14e3e8ab87e/builder/dockerfile/imageprobe.go (about)

     1  package dockerfile // import "github.com/Prakhar-Agarwal-byte/moby/builder/dockerfile"
     2  
     3  import (
     4  	"context"
     5  
     6  	"github.com/Prakhar-Agarwal-byte/moby/api/types/container"
     7  	"github.com/Prakhar-Agarwal-byte/moby/builder"
     8  	"github.com/containerd/log"
     9  )
    10  
    11  // ImageProber exposes an Image cache to the Builder. It supports resetting a
    12  // cache.
    13  type ImageProber interface {
    14  	Reset(ctx context.Context) error
    15  	Probe(parentID string, runConfig *container.Config) (string, error)
    16  }
    17  
    18  type resetFunc func(context.Context) (builder.ImageCache, error)
    19  
    20  type imageProber struct {
    21  	cache       builder.ImageCache
    22  	reset       resetFunc
    23  	cacheBusted bool
    24  }
    25  
    26  func newImageProber(ctx context.Context, cacheBuilder builder.ImageCacheBuilder, cacheFrom []string, noCache bool) (ImageProber, error) {
    27  	if noCache {
    28  		return &nopProber{}, nil
    29  	}
    30  
    31  	reset := func(ctx context.Context) (builder.ImageCache, error) {
    32  		return cacheBuilder.MakeImageCache(ctx, cacheFrom)
    33  	}
    34  
    35  	cache, err := reset(ctx)
    36  	if err != nil {
    37  		return nil, err
    38  	}
    39  	return &imageProber{cache: cache, reset: reset}, nil
    40  }
    41  
    42  func (c *imageProber) Reset(ctx context.Context) error {
    43  	newCache, err := c.reset(ctx)
    44  	if err != nil {
    45  		return err
    46  	}
    47  	c.cache = newCache
    48  	c.cacheBusted = false
    49  	return nil
    50  }
    51  
    52  // Probe checks if cache match can be found for current build instruction.
    53  // It returns the cachedID if there is a hit, and the empty string on miss
    54  func (c *imageProber) Probe(parentID string, runConfig *container.Config) (string, error) {
    55  	if c.cacheBusted {
    56  		return "", nil
    57  	}
    58  	cacheID, err := c.cache.GetCache(parentID, runConfig)
    59  	if err != nil {
    60  		return "", err
    61  	}
    62  	if len(cacheID) == 0 {
    63  		log.G(context.TODO()).Debugf("[BUILDER] Cache miss: %s", runConfig.Cmd)
    64  		c.cacheBusted = true
    65  		return "", nil
    66  	}
    67  	log.G(context.TODO()).Debugf("[BUILDER] Use cached version: %s", runConfig.Cmd)
    68  	return cacheID, nil
    69  }
    70  
    71  type nopProber struct{}
    72  
    73  func (c *nopProber) Reset(ctx context.Context) error {
    74  	return nil
    75  }
    76  
    77  func (c *nopProber) Probe(_ string, _ *container.Config) (string, error) {
    78  	return "", nil
    79  }