thodg/libgit2/tests/odb/sorting.c

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• Hash : a0a1b19a
  Author :
  Date : 2015-10-14T19:31:54
  

  odb: Prioritize alternate backends
  
  For most real use cases, repositories with alternates use them as main
  object storage. Checking the alternate for objects before the main
  repository should result in measurable speedups.
  
  Because of this, we're changing the sorting algorithm to prioritize
  alternates *in cases where two backends have the same priority*. This
  means that the pack backend for the alternate will be checked before the
  pack backend for the main repository *but* both of them will be checked
  before any loose backends.
  

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• tests/odb/sorting.c

• #include "clar_libgit2.h"
  #include "git2/sys/odb_backend.h"
  
  typedef struct {
  	git_odb_backend base;
  	size_t position;
  } fake_backend;
  
  static git_odb_backend *new_backend(size_t position)
  {
  	fake_backend *b;
  
  	b = git__calloc(1, sizeof(fake_backend));
  	if (b == NULL)
  		return NULL;
  
  	b->base.free = (void (*)(git_odb_backend *)) git__free;
  	b->base.version = GIT_ODB_BACKEND_VERSION;
  	b->position = position;
  	return (git_odb_backend *)b;
  }
  
  static void check_backend_sorting(git_odb *odb)
  {
  	size_t i, max_i = git_odb_num_backends(odb);
  	fake_backend *internal;
  
  	for (i = 0; i < max_i; ++i) {
  		cl_git_pass(git_odb_get_backend((git_odb_backend **)&internal, odb, i));
  		cl_assert(internal != NULL);
  		cl_assert_equal_sz(i, internal->position);
  	}
  }
  
  static git_odb *_odb;
  
  void test_odb_sorting__initialize(void)
  {
  	cl_git_pass(git_odb_new(&_odb));
  }
  
  void test_odb_sorting__cleanup(void)
  {
  	git_odb_free(_odb);
  	_odb = NULL;
  }
  
  void test_odb_sorting__basic_backends_sorting(void)
  {
  	cl_git_pass(git_odb_add_backend(_odb, new_backend(0), 5));
  	cl_git_pass(git_odb_add_backend(_odb, new_backend(2), 3));
  	cl_git_pass(git_odb_add_backend(_odb, new_backend(1), 4));
  	cl_git_pass(git_odb_add_backend(_odb, new_backend(3), 1));
  
  	check_backend_sorting(_odb);
  }
  
  void test_odb_sorting__alternate_backends_sorting(void)
  {
  	cl_git_pass(git_odb_add_backend(_odb, new_backend(1), 5));
  	cl_git_pass(git_odb_add_backend(_odb, new_backend(5), 3));
  	cl_git_pass(git_odb_add_backend(_odb, new_backend(3), 4));
  	cl_git_pass(git_odb_add_backend(_odb, new_backend(7), 1));
  	cl_git_pass(git_odb_add_alternate(_odb, new_backend(0), 5));
  	cl_git_pass(git_odb_add_alternate(_odb, new_backend(4), 3));
  	cl_git_pass(git_odb_add_alternate(_odb, new_backend(2), 4));
  	cl_git_pass(git_odb_add_alternate(_odb, new_backend(6), 1));
  
  	check_backend_sorting(_odb);
  }
  

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