"""Performance tests for object store"""
from __future__ import print_function
from time import time
import sys

from .lib import (
    TestBigRepoR
)


class TestObjDBPerformance(TestBigRepoR):

    def test_random_access(self):
        results = [["Iterate Commits"], ["Iterate Blobs"], ["Retrieve Blob Data"]]
        for repo in (self.gitrorepo, self.puregitrorepo):
            # GET COMMITS
            st = time()
            root_commit = repo.commit(repo.head)
            commits = list(root_commit.traverse())
            nc = len(commits)
            elapsed = time() - st

            print("%s: Retrieved %i commits from ObjectStore in %g s ( %f commits / s )"
                  % (type(repo.odb), nc, elapsed, nc / elapsed), file=sys.stderr)
            results[0].append(elapsed)

            # GET TREES
            # walk all trees of all commits
            st = time()
            blobs_per_commit = list()
            nt = 0
            for commit in commits:
                tree = commit.tree
                blobs = list()
                for item in tree.traverse():
                    nt += 1
                    if item.type == 'blob':
                        blobs.append(item)
                    # direct access for speed
                # END while trees are there for walking
                blobs_per_commit.append(blobs)
            # END for each commit
            elapsed = time() - st

            print("%s: Retrieved %i objects from %i commits in %g s ( %f objects / s )"
                  % (type(repo.odb), nt, len(commits), elapsed, nt / elapsed), file=sys.stderr)
            results[1].append(elapsed)

            # GET BLOBS
            st = time()
            nb = 0
            too_many = 15000
            data_bytes = 0
            for blob_list in blobs_per_commit:
                for blob in blob_list:
                    data_bytes += len(blob.data_stream.read())
                # END for each blobsha
                nb += len(blob_list)
                if nb > too_many:
                    break
            # END for each bloblist
            elapsed = time() - st

            msg = "%s: Retrieved %i blob (%i KiB) and their data in %g s ( %f blobs / s, %f KiB / s )"\
                % (type(repo.odb), nb, data_bytes / 1000, elapsed, nb / elapsed, (data_bytes / 1000) / elapsed)
            print(msg, file=sys.stderr)
            results[2].append(elapsed)
        # END for each repo type

        # final results
        for test_name, a, b in results:
            print("%s: %f s vs %f s, pure is %f times slower" % (test_name, a, b, b / a), file=sys.stderr)
        # END for each result
