> Index: subversion/include/svn_diff.h
> ===================================================================
> --- subversion/include/svn_diff.h (revision 1001548)
> +++ subversion/include/svn_diff.h (working copy)
> @@ -112,6 +112,11 @@
(personally I prefer 'svn diff -x-p' to show the function name here)
> svn_error_t *(*datasource_open)(void *diff_baton,
> svn_diff_datasource_e datasource);
>
> + /** Open the datasources of type @a datasources. */
> + svn_error_t *(*datasources_open)(void *diff_baton, apr_off_t *prefix_lines,
> + svn_diff_datasource_e datasource0,
> + svn_diff_datasource_e datasource1);
> +
So, you're extending the svn_diff_fns_t struct, which is defined in
a public header.
It's a public struct with no constructor function, so I believe you have
to revv it (into svn_diff_fns2_t) in order to extend it (for binary
compatibility: people allocating this struct and then using a newer
Subversion library at runtime).
If it did have a constructor function, you'd have to extend it only at
the end, and even then make sure that if the added elements are NULL (eg
because an old caller didn't know to fill them) then everything still
worked.
Probably more important to get the logic right than to revv it right
away, though; the latter is a SMOP.
> /** Close the datasource of type @a datasource. */
> svn_error_t *(*datasource_close)(void *diff_baton,
> svn_diff_datasource_e datasource);
> @@ -124,6 +129,9 @@
> void *diff_baton,
> svn_diff_datasource_e datasource);
>
> + /** Get the number of identical prefix lines from the @a diff_baton. */
> + apr_off_t (*get_prefix_lines)(void *diff_baton);
> +
> /** A function for ordering the tokens, resembling 'strcmp' in functionality.
> * @a compare should contain the return value of the comparison:
> * If @a ltoken and @a rtoken are "equal", return 0. If @a ltoken is
> Index: subversion/libsvn_diff/diff_memory.c
> ===================================================================
> --- subversion/libsvn_diff/diff_memory.c (revision 1001548)
> +++ subversion/libsvn_diff/diff_memory.c (working copy)
> @@ -95,7 +95,23 @@
> return SVN_NO_ERROR;
> }
>
> +/* Implements svn_diff_fns_t::datasources_open */
> +static svn_error_t *
> +datasources_open(void *baton, apr_off_t *prefix_lines,
> + svn_diff_datasource_e datasource0,
> + svn_diff_datasource_e datasource1)
> +{
> + /* Do nothing: everything is already there and initialized to 0 */
> + return SVN_NO_ERROR;
> +}
>
> +/* Implements svn_diff_fns_t::datasource_get_prefix_lines */
> +static apr_off_t
> +get_prefix_lines(void *baton)
> +{
> + return 0;
> +}
> +
> /* Implements svn_diff_fns_t::datasource_close */
> static svn_error_t *
> datasource_close(void *baton, svn_diff_datasource_e datasource)
> @@ -189,8 +205,10 @@
> static const svn_diff_fns_t svn_diff__mem_vtable =
> {
> datasource_open,
> + datasources_open,
> datasource_close,
> datasource_get_next_token,
> + get_prefix_lines,
> token_compare,
> token_discard,
> token_discard_all
> Index: subversion/libsvn_diff/diff_file.c
> ===================================================================
> --- subversion/libsvn_diff/diff_file.c (revision 1001548)
> +++ subversion/libsvn_diff/diff_file.c (working copy)
> @@ -77,6 +77,10 @@
> char *curp[4];
> char *endp[4];
>
> + apr_off_t prefix_lines;
> + int suffix_start_chunk[4];
> + apr_off_t suffix_offset_in_chunk[4];
> +
> /* List of free tokens that may be reused. */
> svn_diff__file_token_t *tokens;
>
> @@ -233,7 +237,330 @@
> curp, length, 0, file_baton->pool);
> }
>
> +static svn_error_t *
> +increment_pointer_or_chunk(svn_diff__file_baton_t *file_baton,
> + char **curp, char **endp, int *chunk_number,
> + char *buffer, apr_off_t last_chunk_number, int idx)
> +{
> + apr_off_t length;
>
> + if ((*curp) == (*endp) - 1)
> + {
> + if (*chunk_number == last_chunk_number)
> + (*curp)++; /* *curp == *endp with last chunk signals end of file */
> + else
> + {
> + (*chunk_number)++;
> + length = *chunk_number == last_chunk_number ?
> + offset_in_chunk(file_baton->size[idx]) : CHUNK_SIZE;
> + SVN_ERR(read_chunk(file_baton->file[idx],
> + file_baton->path[idx],
> + buffer, length,
> + chunk_to_offset(*chunk_number),
> + file_baton->pool));
> + *endp = buffer + length;
> + *curp = buffer;
> + }
> + }
> + else
> + {
> + (*curp)++;
> + }
> +
> + return SVN_NO_ERROR;
> +}
> +
> +static svn_error_t *
> +decrement_pointer_or_chunk(svn_diff__file_baton_t *file_baton,
> + char **curp, char **endp, int *chunk_number,
> + char *buffer, int idx)
> +{
> + if (*curp == buffer)
> + {
> + if (*chunk_number == 0)
> + (*chunk_number)--; /* *chunk_number == -1 signals beginning of file */
> + else
> + {
> + (*chunk_number)--;
> + SVN_ERR(read_chunk(file_baton->file[idx],
> + file_baton->path[idx],
> + buffer, CHUNK_SIZE,
> + chunk_to_offset(*chunk_number),
> + file_baton->pool));
> + *endp = buffer + CHUNK_SIZE;
> + *curp = *endp - 1;
> + }
> + }
> + else
> + {
> + (*curp)--;
> + }
> +
> + return SVN_NO_ERROR;
> +}
> +
> +/* Find the identical prefix for idx0 and idx1, counting number of lines.
> + * After this function is finished, the buffers, chunks, curp's and endp's
> + * of the file_baton are set to point at the first byte after the prefix. */
> +static svn_error_t *
> +find_identical_prefix(svn_diff__file_baton_t *file_baton,
> + svn_boolean_t *at_least_one_end_reached,
> + int idx0, int idx1)
> +{
> + apr_off_t last_chunk0, last_chunk1;
> +
> + last_chunk0 = offset_to_chunk(file_baton->size[idx0]);
> + last_chunk1 = offset_to_chunk(file_baton->size[idx1]);
> + *at_least_one_end_reached = FALSE;
> +
> + file_baton->prefix_lines = 0;
> + while (*file_baton->curp[idx0] == *file_baton->curp[idx1]
> + && !*at_least_one_end_reached)
> + {
> + /* ### This will only work for \n and \r\n, not for \r */
> + if (*file_baton->curp[idx0] == '\n')
> + file_baton->prefix_lines++;
> + SVN_ERR(increment_pointer_or_chunk(file_baton,
> + &file_baton->curp[idx0],
> + &file_baton->endp[idx0],
> + &file_baton->chunk[idx0],
> + file_baton->buffer[idx0],
> + last_chunk0, idx0));
> + SVN_ERR(increment_pointer_or_chunk(file_baton,
> + &file_baton->curp[idx1],
> + &file_baton->endp[idx1],
> + &file_baton->chunk[idx1],
> + file_baton->buffer[idx1],
> + last_chunk1, idx1));
> + *at_least_one_end_reached =
> + file_baton->curp[idx0] == file_baton->endp[idx0]
> + || file_baton->curp[idx1] == file_baton->endp[idx1];
> + }
> +
> + /* If both files reached their end (i.e. are fully identical), we're done */
> + if (file_baton->curp[idx0] == file_baton->endp[idx0]
> + && file_baton->curp[idx1] == file_baton->endp[idx1])
> + return SVN_NO_ERROR;
> +
> + /* Back up to the last newline */
> + do
> + {
> + SVN_ERR(decrement_pointer_or_chunk(file_baton,
> + &file_baton->curp[idx0],
> + &file_baton->endp[idx0],
> + &file_baton->chunk[idx0],
> + file_baton->buffer[idx0],
> + idx0));
> + SVN_ERR(decrement_pointer_or_chunk(file_baton,
> + &file_baton->curp[idx1],
> + &file_baton->endp[idx1],
> + &file_baton->chunk[idx1],
> + file_baton->buffer[idx1],
> + idx1));
> + } while (*file_baton->curp[idx0] != '\n'
> + && file_baton->chunk[idx0] != -1
> + && file_baton->chunk[idx1] != -1);
> +
> + /* slide one byte forward, to point past the \n */
> + if (file_baton->chunk[idx0] == -1)
> + file_baton->chunk[idx0] = 0; /* point to beginning of file again */
> + else
> + SVN_ERR(increment_pointer_or_chunk(file_baton,
> + &file_baton->curp[idx0],
> + &file_baton->endp[idx0],
> + &file_baton->chunk[idx0],
> + file_baton->buffer[idx0],
> + last_chunk0, idx0));
> + if (file_baton->chunk[idx1] == -1)
> + file_baton->chunk[idx1] = 0; /* point to beginning of file again */
> + else
> + SVN_ERR(increment_pointer_or_chunk(file_baton,
> + &file_baton->curp[idx1],
> + &file_baton->endp[idx1],
> + &file_baton->chunk[idx1],
> + file_baton->buffer[idx1],
> + last_chunk1, idx1));
> +
> + return SVN_NO_ERROR;
> +}
> +
> +/* Find the identical suffix for idx0 and idx1. Before this function is called
> + * the file_baton's curp's and chunks should be positioned right after the
> + * identical prefix (which is the case after find_identical_prefix),
> + * so we can determine where suffix scanning should ultimately stop. */
> +static svn_error_t *
> +find_identical_suffix(svn_diff__file_baton_t *file_baton,
> + int idx0, int idx1)
> +{
> + char *suffix_buffer0, *suffix_buffer1;
> + int suffix_chunk0, suffix_chunk1;
> + apr_off_t length0, length1;
> + apr_off_t last_chunk0, last_chunk1;
> + apr_off_t suffix_min_offset0;
> + apr_off_t suffix_min_chunk0;
> + char *curp0, *curp1;
> + char *endp0, *endp1;
> +
> + last_chunk0 = offset_to_chunk(file_baton->size[idx0]);
> + last_chunk1 = offset_to_chunk(file_baton->size[idx1]);
> +
> + /* position everything at last chunk, pointer to last byte */
> + suffix_buffer0 = apr_palloc(file_baton->pool,
> + (apr_size_t) (file_baton->size[idx0] > CHUNK_SIZE ?
> + CHUNK_SIZE : file_baton->size[idx0]));
> + suffix_chunk0 = last_chunk0;
> + length0 = file_baton->size[idx0] % CHUNK_SIZE;
> + SVN_ERR(read_chunk(file_baton->file[idx0], file_baton->path[idx0],
> + suffix_buffer0, length0,
> + chunk_to_offset(suffix_chunk0),
> + file_baton->pool));
> + endp0 = suffix_buffer0 + length0;
> + curp0 = endp0 - 1;
> +
> + suffix_buffer1 = apr_palloc(file_baton->pool,
> + (apr_size_t) (file_baton->size[idx1] > CHUNK_SIZE ?
> + CHUNK_SIZE : file_baton->size[idx1]));
> + suffix_chunk1 = last_chunk1;
> + length1 = file_baton->size[idx1] % CHUNK_SIZE;
> + SVN_ERR(read_chunk(file_baton->file[idx1], file_baton->path[idx1],
> + suffix_buffer1, length1,
> + chunk_to_offset(suffix_chunk1),
> + file_baton->pool));
> + endp1 = suffix_buffer1 + length1;
> + curp1 = endp1 - 1;
> +
> + /* Get the chunk and pointer offset at which we should stop scanning
> + * backward for the identical suffix. This is just past the prefix. */
> + suffix_min_chunk0 = file_baton->chunk[idx0];
> + suffix_min_offset0 = file_baton->curp[idx0] - file_baton->buffer[idx0];
> + if (file_baton->size[idx0] > file_baton->size[idx1])
> + {
> + suffix_min_chunk0 +=
> + (file_baton->size[idx0] - file_baton->size[idx1]) / CHUNK_SIZE;
> + suffix_min_offset0 +=
> + (file_baton->size[idx0] - file_baton->size[idx1]) % CHUNK_SIZE;
> + }
> +
> + /* Scan backwards until mismatch or until we are where the prefix ended */
> + while (*curp0 == *curp1 && suffix_chunk0 != -1 && suffix_chunk1 != -1
> + && !(suffix_chunk0 == suffix_min_chunk0
> + && (curp0 - suffix_buffer0) == suffix_min_offset0))
> + {
> + SVN_ERR(decrement_pointer_or_chunk(file_baton, &curp0, &endp0,
> + &suffix_chunk0, suffix_buffer0,
> + idx0));
> + SVN_ERR(decrement_pointer_or_chunk(file_baton, &curp1, &endp1,
> + &suffix_chunk1, suffix_buffer1,
> + idx1));
> + }
> +
> + /* slide one byte forward, to point at the first byte of common suffix */
> + if (suffix_chunk0 == -1)
> + suffix_chunk0 = 0; /* point to beginning of file again */
> + else
> + SVN_ERR(increment_pointer_or_chunk(file_baton, &curp0, &endp0,
> + &suffix_chunk0, suffix_buffer0,
> + last_chunk0, idx0));
> + if (suffix_chunk1 == -1)
> + suffix_chunk1 = 0; /* point to beginning of file again */
> + else
> + SVN_ERR(increment_pointer_or_chunk(file_baton, &curp1, &endp1,
> + &suffix_chunk1, suffix_buffer1,
> + last_chunk1, idx1));
> +
> + /* skip to just after a newline */
> + while (*curp0 != '\n' && !(curp0 == endp0 || curp1 == endp1))
> + {
> + SVN_ERR(increment_pointer_or_chunk(file_baton, &curp0, &endp0,
> + &suffix_chunk0, suffix_buffer0,
> + last_chunk0, idx0));
> + SVN_ERR(increment_pointer_or_chunk(file_baton, &curp1, &endp1,
> + &suffix_chunk1, suffix_buffer1,
> + last_chunk1, idx1));
> + }
> +
> + /* slide one more byte, to point past the \n */
> + SVN_ERR(increment_pointer_or_chunk(file_baton, &curp0, &endp0,
> + &suffix_chunk0, suffix_buffer0,
> + last_chunk0, idx0));
> + SVN_ERR(increment_pointer_or_chunk(file_baton, &curp1, &endp1,
> + &suffix_chunk1, suffix_buffer1,
> + last_chunk1, idx1));
> +
> + file_baton->suffix_start_chunk[idx0] = suffix_chunk0;
> + file_baton->suffix_start_chunk[idx1] = suffix_chunk1;
> + file_baton->suffix_offset_in_chunk[idx0] = curp0 - suffix_buffer0;
> + file_baton->suffix_offset_in_chunk[idx1] = curp1 - suffix_buffer1;
> +
> + return SVN_NO_ERROR;
> +}
> +
> +/* Implements svn_diff_fns_t::datasource_open */
> +static svn_error_t *
> +datasources_open(void *baton, apr_off_t *prefix_lines,
> + svn_diff_datasource_e datasource0,
> + svn_diff_datasource_e datasource1)
> +{
> + svn_diff__file_baton_t *file_baton = baton;
> + int idx0, idx1;
> + apr_finfo_t finfo0, finfo1;
> + apr_off_t length0, length1;
> + svn_boolean_t at_least_one_end_reached;
> +
> + /* Open datasource0 and read first chunk */
> + idx0 = datasource_to_index(datasource0);
> + SVN_ERR(svn_io_file_open(&file_baton->file[idx0], file_baton->path[idx0],
> + APR_READ, APR_OS_DEFAULT, file_baton->pool));
> + SVN_ERR(svn_io_file_info_get(&finfo0, APR_FINFO_SIZE,
> + file_baton->file[idx0], file_baton->pool));
> + file_baton->size[idx0] = finfo0.size;
> + length0 = (apr_off_t) (finfo0.size > CHUNK_SIZE ? CHUNK_SIZE : finfo0.size);
> + file_baton->buffer[idx0] = apr_palloc(file_baton->pool, (apr_size_t) length0);
> + SVN_ERR(read_chunk(file_baton->file[idx0], file_baton->path[idx0],
> + file_baton->buffer[idx0], length0, 0, file_baton->pool));
> + file_baton->endp[idx0] = file_baton->buffer[idx0] + length0;
> + file_baton->curp[idx0] = file_baton->buffer[idx0];
> +
> + /* Open datasource1 and read first chunk */
> + idx1 = datasource_to_index(datasource1);
> + SVN_ERR(svn_io_file_open(&file_baton->file[idx1], file_baton->path[idx1],
> + APR_READ, APR_OS_DEFAULT, file_baton->pool));
> + SVN_ERR(svn_io_file_info_get(&finfo1, APR_FINFO_SIZE,
> + file_baton->file[idx1], file_baton->pool));
> + file_baton->size[idx1] = finfo1.size;
> + length1 = (apr_off_t) (finfo1.size > CHUNK_SIZE ? CHUNK_SIZE : finfo1.size);
> + file_baton->buffer[idx1] = apr_palloc(file_baton->pool, (apr_size_t) length1);
> + SVN_ERR(read_chunk(file_baton->file[idx1], file_baton->path[idx1],
> + file_baton->buffer[idx1], length1, 0, file_baton->pool));
> + file_baton->endp[idx1] = file_baton->buffer[idx1] + length1;
> + file_baton->curp[idx1] = file_baton->buffer[idx1];
> +
> + if (length0 == 0 || length1 == 0)
> + /* there will not be any identical prefix/suffix, so we're done */
> + return SVN_NO_ERROR;
> +
> + SVN_ERR(find_identical_prefix(file_baton, &at_least_one_end_reached,
> + idx0, idx1));
> + *prefix_lines = file_baton->prefix_lines;
> +
> + if (at_least_one_end_reached)
> + /* at least one file consisted totally of identical prefix,
> + * so there will be no identical suffix. We're done. */
> + return SVN_NO_ERROR;
> +
> + SVN_ERR(find_identical_suffix(file_baton, idx0, idx1));
> +
> + return SVN_NO_ERROR;
> +}
> +
> +static apr_off_t
> +get_prefix_lines(void *baton)
> +{
> + svn_diff__file_baton_t *file_baton = baton;
> +
> + return file_baton->prefix_lines;
> +}
> +
> /* Implements svn_diff_fns_t::datasource_close */
> static svn_error_t *
> datasource_close(void *baton, svn_diff_datasource_e datasource)
> @@ -277,6 +604,11 @@
> return SVN_NO_ERROR;
> }
>
> + if (file_baton->suffix_start_chunk[idx] || file_baton->suffix_offset_in_chunk[idx])
> + if (file_baton->chunk[idx] == file_baton->suffix_start_chunk[idx]
> + && (curp - file_baton->buffer[idx]) == file_baton->suffix_offset_in_chunk[idx])
> + return SVN_NO_ERROR;
> +
> /* Get a new token */
> file_token = file_baton->tokens;
> if (file_token)
> @@ -526,8 +858,10 @@
> static const svn_diff_fns_t svn_diff__file_vtable =
> {
> datasource_open,
> + datasources_open,
> datasource_close,
> datasource_get_next_token,
> + get_prefix_lines,
> token_compare,
> token_discard,
> token_discard_all
> Index: subversion/libsvn_diff/diff.h
> ===================================================================
> --- subversion/libsvn_diff/diff.h (revision 1001548)
> +++ subversion/libsvn_diff/diff.h (working copy)
> @@ -111,6 +111,7 @@
> void *diff_baton,
> const svn_diff_fns_t *vtable,
> svn_diff_datasource_e datasource,
> + svn_boolean_t datasource_opened,
> apr_pool_t *pool);
>
>
> Index: subversion/libsvn_diff/token.c
> ===================================================================
> --- subversion/libsvn_diff/token.c (revision 1001548)
> +++ subversion/libsvn_diff/token.c (working copy)
> @@ -139,6 +139,7 @@
> void *diff_baton,
> const svn_diff_fns_t *vtable,
> svn_diff_datasource_e datasource,
> + svn_boolean_t datasource_opened,
> apr_pool_t *pool)
> {
> svn_diff__position_t *start_position;
> @@ -152,10 +153,11 @@
> *position_list = NULL;
>
>
> - SVN_ERR(vtable->datasource_open(diff_baton, datasource));
> + if (!datasource_opened)
> + SVN_ERR(vtable->datasource_open(diff_baton, datasource));
>
> position_ref = &start_position;
> - offset = 0;
> + offset = vtable->get_prefix_lines(diff_baton);
> hash = 0; /* The callback fn doesn't need to touch it per se */
> while (1)
> {
> Index: subversion/libsvn_diff/diff.c
> ===================================================================
> --- subversion/libsvn_diff/diff.c (revision 1001548)
> +++ subversion/libsvn_diff/diff.c (working copy)
> @@ -43,6 +43,22 @@
> svn_diff_t *diff;
> svn_diff_t **diff_ref = &diff;
>
> + if (want_common && (original_start > 1))
> + {
> + /* we have a prefix to skip */
> + (*diff_ref) = apr_palloc(pool, sizeof(**diff_ref));
> +
> + (*diff_ref)->type = svn_diff__type_common;
> + (*diff_ref)->original_start = 0;
> + (*diff_ref)->original_length = original_start - 1;
> + (*diff_ref)->modified_start = 0;
> + (*diff_ref)->modified_length = modified_start - 1;
> + (*diff_ref)->latest_start = 0;
> + (*diff_ref)->latest_length = 0;
> +
> + diff_ref = &(*diff_ref)->next;
> + }
> +
> while (1)
> {
> if (original_start < lcs->position[0]->offset
> @@ -108,6 +124,7 @@
> svn_diff__lcs_t *lcs;
> apr_pool_t *subpool;
> apr_pool_t *treepool;
> + apr_off_t prefix_lines = 0;
>
> *diff = NULL;
>
> @@ -116,17 +133,22 @@
>
> svn_diff__tree_create(&tree, treepool);
>
> + SVN_ERR(vtable->datasources_open(diff_baton, &prefix_lines,
> + svn_diff_datasource_original, svn_diff_datasource_modified));
> +
> /* Insert the data into the tree */
> SVN_ERR(svn_diff__get_tokens(&position_list[0],
> tree,
> diff_baton, vtable,
> svn_diff_datasource_original,
> + TRUE,
> subpool));
>
> SVN_ERR(svn_diff__get_tokens(&position_list[1],
> tree,
> diff_baton, vtable,
> svn_diff_datasource_modified,
> + TRUE,
> subpool));
>
> /* The cool part is that we don't need the tokens anymore.
> @@ -142,7 +164,7 @@
> lcs = svn_diff__lcs(position_list[0], position_list[1], subpool);
>
> /* Produce the diff */
> - *diff = svn_diff__diff(lcs, 1, 1, TRUE, pool);
> + *diff = svn_diff__diff(lcs, prefix_lines + 1, prefix_lines + 1, TRUE, pool);
>
> /* Get rid of all the data we don't have a use for anymore */
> svn_pool_destroy(subpool);
> Index: subversion/libsvn_diff/diff3.c
> ===================================================================
> --- subversion/libsvn_diff/diff3.c (revision 1001548)
> +++ subversion/libsvn_diff/diff3.c (working copy)
> @@ -267,18 +267,21 @@
> tree,
> diff_baton, vtable,
> svn_diff_datasource_original,
> + FALSE,
> subpool));
>
> SVN_ERR(svn_diff__get_tokens(&position_list[1],
> tree,
> diff_baton, vtable,
> svn_diff_datasource_modified,
> + FALSE,
> subpool));
>
> SVN_ERR(svn_diff__get_tokens(&position_list[2],
> tree,
> diff_baton, vtable,
> svn_diff_datasource_latest,
> + FALSE,
> subpool));
>
> /* Get rid of the tokens, we don't need them to calc the diff */
> Index: subversion/libsvn_diff/diff4.c
> ===================================================================
> --- subversion/libsvn_diff/diff4.c (revision 1001548)
> +++ subversion/libsvn_diff/diff4.c (working copy)
> @@ -194,24 +194,28 @@
> tree,
> diff_baton, vtable,
> svn_diff_datasource_original,
> + FALSE,
> subpool2));
>
> SVN_ERR(svn_diff__get_tokens(&position_list[1],
> tree,
> diff_baton, vtable,
> svn_diff_datasource_modified,
> + FALSE,
> subpool));
>
> SVN_ERR(svn_diff__get_tokens(&position_list[2],
> tree,
> diff_baton, vtable,
> svn_diff_datasource_latest,
> + FALSE,
> subpool));
>
> SVN_ERR(svn_diff__get_tokens(&position_list[3],
> tree,
> diff_baton, vtable,
> svn_diff_datasource_ancestor,
> + FALSE,
> subpool2));
>
> /* Get rid of the tokens, we don't need them to calc the diff */
Received on 2010-09-28 16:12:30 CEST