Using the cache in this step will **save** you a lot of **time** when building the image again and again during development, instead of **downloading and installing** all the dependencies **every time**.

5. Copy the `./app` directory inside the `/code` directory.

    As this has all the code which is what **changes most frequently** the Docker **cache** won't be used for this or any **following steps** easily.

So, during that time, the computer can go and do some other work, while "slow-file" 📝 finishes.

Then the computer / program 🤖 will come back every time it has a chance because it's waiting again, or whenever it 🤖 finished all the work it had at that point. And it 🤖 will see if any of the tasks it was waiting for have already finished, doing whatever it had to do.

	// used when o.Versioned is false
	if !o.Versioned {
		resolver.requestedVersions = 1
	}
	var limit int
	if o.Limit > 0 && o.StopDiskAtLimit {
		// Over-read by 4 + 1 for every 16 in limit to give some space for resolver,
		// allow for truncating the list and know if we have more results.
		limit = o.Limit + 4 + (o.Limit / 16)
	}
	ctxDone := ctx.Done()

	curr fileReader // Reader for current file entry
	blk  block      // Buffer to use as temporary local storage

	// err is a persistent error.
	// It is only the responsibility of every exported method of Reader to
	// ensure that this error is sticky.
	err error
}

type fileReader interface {
	io.Reader
	fileState

	WriteTo(io.Writer) (int64, error)
}

  //   done on a path element by element basis. A path element refers is the
  //   list of labels in the path split by the '/' separator. A request is a
  //   match for path p if every p is an element-wise prefix of p of the
  //   request path. Note that if the last element of the path is a substring
  //   of the last element in request path, it is not a match (e.g. /foo/bar

)

// Temp files created in default Tmp dir
var globalTestTmpDir = os.TempDir()

// reseed - returns a new seed every time the function is called.
func reseed() uint32 {
	return uint32(time.Now().UnixNano() + int64(os.Getpid()))
}

// nextSuffix - provides a new unique suffix every time the function is called.
func nextSuffix() string {
	randmu.Lock()
	r := randN
	// Initial seed required, generate one.

      if ((readCount.incrementAndGet() & DRAIN_THRESHOLD) == 0) {
        runCleanup();
      }
    }

    /**
     * Performs routine cleanup prior to executing a write. This should be called every time a write
     * thread acquires the segment lock, immediately after acquiring the lock.
     */
    @GuardedBy("this")
    void preWriteCleanup() {
      runLockedCleanup();
    }

sending an item acquires the semaphore, and receiving an item releases
the semaphore.
This is a common idiom for limiting concurrency.
</p>

<p>
This program starts a goroutine for every entry in the work list, but the
goroutines coordinate using the <code>limit</code> channel to ensure
that at most three are running work functions at a time.
</p>

<pre>
var limit = make(chan int, 3)

	// Start the disk monitoring and connect routine.
	if !globalIsTesting {
		go s.monitorAndConnectEndpoints(ctx, defaultMonitorConnectEndpointInterval)
	}

	return s, nil
}

// cleanup ".trash/" folder every 5m minutes with sufficient sleep cycles, between each
// deletes a dynamic sleeper is used with a factor of 10 ratio with max delay between
// deletes to be 2 seconds.

					// clean import.
					err := globalIAMSys.DeleteServiceAccount(ctx, svcAcctReq.AccessKey, true)
					if err != nil {
						delErr := fmt.Errorf("failed to delete existing service account (%s) before importing it: %w", svcAcctReq.AccessKey, err)
						writeErrorResponseJSON(ctx, w, importError(ctx, delErr, allSvcAcctsFile, user), r.URL)
						return
					}
				}
				opts := newServiceAccountOpts{