}
}
+/* A mapping (correspondence) between entries of FILE1 and of FILE2. */
+struct entries_mapping
+{
+ struct changelog_file *file1;
+ struct changelog_file *file2;
+ /* Mapping from indices in FILE1 to indices in FILE2.
+ A value -1 means that the entry from FILE1 is not found in FILE2.
+ A value -2 means that it has not yet been computed. */
+ ssize_t *index_mapping;
+ /* Mapping from indices in FILE2 to indices in FILE1.
+ A value -1 means that the entry from FILE2 is not found in FILE1.
+ A value -2 means that it has not yet been computed. */
+ ssize_t *index_mapping_reverse;
+};
+
+/* Look up (or lazily compute) the mapping of an entry in FILE1.
+ i is the index in FILE1.
+ Return the index in FILE2, or -1 when the entry is not found in FILE2. */
+static ssize_t
+entries_mapping_get (struct entries_mapping *mapping, ssize_t i)
+{
+ if (mapping->index_mapping[i] < -1)
+ {
+ struct changelog_file *file1 = mapping->file1;
+ struct changelog_file *file2 = mapping->file2;
+ size_t n1 = file1->num_entries;
+ size_t n2 = file2->num_entries;
+ struct entry *entry_i = file1->entries[i];
+ ssize_t j;
+
+ /* Search whether it approximately occurs in file2. */
+ ssize_t best_j = -1;
+ double best_j_similarity = 0.0;
+ for (j = n2 - 1; j >= 0; j--)
+ if (mapping->index_mapping_reverse[j] < 0)
+ {
+ double similarity =
+ entry_fstrcmp (entry_i, file2->entries[j], best_j_similarity);
+ if (similarity > best_j_similarity)
+ {
+ best_j = j;
+ best_j_similarity = similarity;
+ }
+ }
+ if (best_j_similarity >= FSTRCMP_THRESHOLD)
+ {
+ /* Found a similar entry in file2. */
+ struct entry *entry_j = file2->entries[best_j];
+ /* Search whether it approximately occurs in file1 at index i. */
+ ssize_t best_i = -1;
+ double best_i_similarity = 0.0;
+ ssize_t ii;
+ for (ii = n1 - 1; ii >= 0; ii--)
+ if (mapping->index_mapping[ii] < 0)
+ {
+ double similarity =
+ entry_fstrcmp (file1->entries[ii], entry_j,
+ best_i_similarity);
+ if (similarity > best_i_similarity)
+ {
+ best_i = ii;
+ best_i_similarity = similarity;
+ }
+ }
+ if (best_i_similarity >= FSTRCMP_THRESHOLD && best_i == i)
+ {
+ mapping->index_mapping[i] = best_j;
+ mapping->index_mapping_reverse[best_j] = i;
+ }
+ }
+ if (mapping->index_mapping[i] < -1)
+ /* It does not approximately occur in FILE2.
+ Remember it, for next time. */
+ mapping->index_mapping[i] = -1;
+ }
+ return mapping->index_mapping[i];
+}
+
+/* Look up (or lazily compute) the mapping of an entry in FILE2.
+ j is the index in FILE2.
+ Return the index in FILE1, or -1 when the entry is not found in FILE1. */
+static ssize_t
+entries_mapping_reverse_get (struct entries_mapping *mapping, ssize_t j)
+{
+ if (mapping->index_mapping_reverse[j] < -1)
+ {
+ struct changelog_file *file1 = mapping->file1;
+ struct changelog_file *file2 = mapping->file2;
+ size_t n1 = file1->num_entries;
+ size_t n2 = file2->num_entries;
+ struct entry *entry_j = file2->entries[j];
+ ssize_t i;
+
+ /* Search whether it approximately occurs in file1. */
+ ssize_t best_i = -1;
+ double best_i_similarity = 0.0;
+ for (i = n1 - 1; i >= 0; i--)
+ if (mapping->index_mapping[i] < 0)
+ {
+ double similarity =
+ entry_fstrcmp (file1->entries[i], entry_j, best_i_similarity);
+ if (similarity > best_i_similarity)
+ {
+ best_i = i;
+ best_i_similarity = similarity;
+ }
+ }
+ if (best_i_similarity >= FSTRCMP_THRESHOLD)
+ {
+ /* Found a similar entry in file1. */
+ struct entry *entry_i = file1->entries[best_i];
+ /* Search whether it approximately occurs in file2 at index j. */
+ ssize_t best_j = -1;
+ double best_j_similarity = 0.0;
+ ssize_t jj;
+ for (jj = n2 - 1; jj >= 0; jj--)
+ if (mapping->index_mapping_reverse[jj] < 0)
+ {
+ double similarity =
+ entry_fstrcmp (entry_i, file2->entries[jj],
+ best_j_similarity);
+ if (similarity > best_j_similarity)
+ {
+ best_j = jj;
+ best_j_similarity = similarity;
+ }
+ }
+ if (best_j_similarity >= FSTRCMP_THRESHOLD && best_j == j)
+ {
+ mapping->index_mapping_reverse[j] = best_i;
+ mapping->index_mapping[best_i] = j;
+ }
+ }
+ if (mapping->index_mapping_reverse[j] < -1)
+ /* It does not approximately occur in FILE1.
+ Remember it, for next time. */
+ mapping->index_mapping_reverse[j] = -1;
+ }
+ return mapping->index_mapping_reverse[j];
+}
+
/* Compute a mapping (correspondence) between entries of FILE1 and of FILE2.
- Return a set of two arrays:
- - An array mapping FILE1 indices to FILE2 indices (or -1 when the entry
- from FILE1 is not found in FILE2).
- - An array mapping FILE2 indices to FILE1 indices (or -1 when the entry
- from FILE2 is not found in FILE1).
The correspondence also takes into account small modifications; i.e. the
indicated relation is not equality of entries but best-match similarity
- of entries. */
+ of entries.
+ If FULL is true, the maximum of matching is done up-front. If it is false,
+ it is done in a lazy way through the functions entries_mapping_get and
+ entries_mapping_reverse_get.
+ Return the result in *RESULT. */
static void
compute_mapping (struct changelog_file *file1, struct changelog_file *file2,
- ssize_t *result[2])
+ bool full,
+ struct entries_mapping *result)
{
/* Mapping from indices in file1 to indices in file2. */
ssize_t *index_mapping;
index_mapping = XNMALLOC (n1, ssize_t);
for (i = 0; i < n1; i++)
- index_mapping[i] = -1;
+ index_mapping[i] = -2;
index_mapping_reverse = XNMALLOC (n2, ssize_t);
for (j = 0; j < n2; j++)
- index_mapping_reverse[j] = -1;
+ index_mapping_reverse[j] = -2;
for (i = n1 - 1; i >= 0; i--)
/* Take an entry from file1. */
- if (index_mapping[i] < 0)
+ if (index_mapping[i] < -1)
{
struct entry *entry = file1->entries[i];
/* Search whether it occurs in file2. */
}
}
- for (i = n1 - 1; i >= 0; i--)
- /* Take an entry from file1. */
- if (index_mapping[i] < 0)
- {
- struct entry *entry_i = file1->entries[i];
- /* Search whether it approximately occurs in file2. */
- ssize_t best_j = -1;
- double best_j_similarity = 0.0;
- for (j = n2 - 1; j >= 0; j--)
- if (index_mapping_reverse[j] < 0)
- {
- double similarity =
- entry_fstrcmp (entry_i, file2->entries[j], best_j_similarity);
- if (similarity > best_j_similarity)
- {
- best_j = j;
- best_j_similarity = similarity;
- }
- }
- if (best_j_similarity >= FSTRCMP_THRESHOLD)
- {
- /* Found a similar entry in file2. */
- struct entry *entry_j = file2->entries[best_j];
- /* Search whether it approximately occurs in file1 at index i. */
- ssize_t best_i = -1;
- double best_i_similarity = 0.0;
- ssize_t ii;
- for (ii = n1 - 1; ii >= 0; ii--)
- if (index_mapping[ii] < 0)
- {
- double similarity =
- entry_fstrcmp (file1->entries[ii], entry_j,
- best_i_similarity);
- if (similarity > best_i_similarity)
- {
- best_i = ii;
- best_i_similarity = similarity;
- }
- }
- if (best_i_similarity >= FSTRCMP_THRESHOLD && best_i == i)
- {
- index_mapping[i] = best_j;
- index_mapping_reverse[best_j] = i;
- }
- }
- }
+ result->file1 = file1;
+ result->file2 = file2;
+ result->index_mapping = index_mapping;
+ result->index_mapping_reverse = index_mapping_reverse;
- result[0] = index_mapping;
- result[1] = index_mapping_reverse;
+ if (full)
+ for (i = n1 - 1; i >= 0; i--)
+ entries_mapping_get (result, i);
}
/* An "edit" is a textual modification performed by the user, that needs to
struct changelog_file mainstream_file;
struct changelog_file modified_file;
/* Mapping from indices in ancestor_file to indices in mainstream_file. */
- ssize_t *index_mapping;
- /* Mapping from indices in mainstream_file to indices in ancestor_file. */
- ssize_t *index_mapping_reverse;
+ struct entries_mapping mapping;
struct differences diffs;
gl_list_node_t *result_entries_pointers; /* array of pointers into result_entries */
gl_list_t /* <struct entry *> */ result_entries;
/* Compute correspondence between the entries of ancestor_file and of
mainstream_file. */
- {
- ssize_t *result[2];
- compute_mapping (&ancestor_file, &mainstream_file, result);
- index_mapping = result[0];
- index_mapping_reverse = result[1];
- }
+ compute_mapping (&ancestor_file, &mainstream_file, false, &mapping);
+ (void) entries_mapping_reverse_get; /* avoid gcc "defined but not" warning */
/* Compute differences between the entries of ancestor_file and of
modified_file. */
ancestor_file.entries[i_after]. See whether these two
entries still exist in mainstream_file and are still
consecutive. */
- k_before = index_mapping[i_before];
+ k_before = entries_mapping_get (&mapping, i_before);
k_after = (i_after == ancestor_file.num_entries
? mainstream_file.num_entries
- : index_mapping[i_after]);
+ : entries_mapping_get (&mapping, i_after));
if (k_before >= 0 && k_after >= 0 && k_after == k_before + 1)
{
/* Yes, the entry before and after are still neighbours
for (i = edit->i1; i <= edit->i2; i++)
{
struct entry *removed_entry = ancestor_file.entries[i];
- ssize_t k = index_mapping[i];
+ ssize_t k = entries_mapping_get (&mapping, i);
if (k >= 0
&& entry_equals (removed_entry,
mainstream_file.entries[k]))
? split[1]
: modified_file.entries[j]);
size_t i = j + edit->i2 - edit->j2;
- ssize_t k = index_mapping[i];
+ ssize_t k = entries_mapping_get (&mapping, i);
if (k >= 0
&& entry_equals (ancestor_file.entries[i],
mainstream_file.entries[k]))
{
struct entry *changed_entry = modified_file.entries[j];
size_t i = j + edit->i2 - edit->j2;
- ssize_t k = index_mapping[i];
+ ssize_t k = entries_mapping_get (&mapping, i);
if (k >= 0
&& entry_equals (ancestor_file.entries[i],
mainstream_file.entries[k]))
See whether this entry and the following num_changed
entries still exist in mainstream_file and are still
consecutive. */
- k_before = index_mapping[i_before];
+ k_before = entries_mapping_get (&mapping, i_before);
linear = (k_before >= 0);
if (linear)
{
size_t i;
for (i = i_before + 1; i <= i_before + num_changed; i++)
- if (index_mapping[i] != k_before + (i - i_before))
+ if (entries_mapping_get (&mapping, i) != k_before + (i - i_before))
{
linear = false;
break;
{
struct entry *changed_entry = modified_file.entries[j];
size_t i = j + edit->i2 - edit->j2;
- ssize_t k = index_mapping[i];
+ ssize_t k = entries_mapping_get (&mapping, i);
ASSERT (k >= 0);
if (entry_equals (ancestor_file.entries[i],
mainstream_file.entries[k]))
ssize_t k_first;
bool linear_unchanged;
i_first = edit->i1;
- k_first = index_mapping[i_first];
+ k_first = entries_mapping_get (&mapping, i_first);
linear_unchanged =
(k_first >= 0
&& entry_equals (ancestor_file.entries[i_first],
{
size_t i;
for (i = i_first + 1; i <= edit->i2; i++)
- if (!(index_mapping[i] == k_first + (i - i_first)
+ if (!(entries_mapping_get (&mapping, i) == k_first + (i - i_first)
&& entry_equals (ancestor_file.entries[i],
- mainstream_file.entries[index_mapping[i]])))
+ mainstream_file.entries[entries_mapping_get (&mapping, i)])))
{
linear_unchanged = false;
break;
}
for (i = edit->i1; i <= edit->i2; i++)
{
- ssize_t k = index_mapping[i];
+ ssize_t k = entries_mapping_get (&mapping, i);
ASSERT (k >= 0);
ASSERT (entry_equals (ancestor_file.entries[i],
mainstream_file.entries[k]));
projects / pspp / commitdiff