diff options
Diffstat (limited to 'editor.c')
| -rw-r--r-- | editor.c | 116 |
1 files changed, 113 insertions, 3 deletions
@@ -13,6 +13,7 @@ #include "editor.h" #define MAX(a, b) ((a) < (b) ? (b) : (a)) +#define MIN(a, b) ((a) > (b) ? (b) : (a)) #define BUFFER_SIZE (1 << 20) @@ -44,7 +45,6 @@ struct Piece { const char *data; /* pointer into a Buffer holding the data */ size_t len; /* the lenght in number of bytes starting from content */ int index; /* unique index identifiying the piece */ - // size_t line_count; }; /* used to transform a global position (byte offset starting from the begining @@ -61,7 +61,6 @@ typedef struct { typedef struct { Piece *start, *end; /* start/end of the span */ size_t len; /* the sum of the lenghts of the pieces which form this span */ - // size_t line_count; } Span; /* A Change keeps all needed information to redo/undo an insertion/deletion. */ @@ -82,6 +81,11 @@ struct Action { time_t time; /* when the first change of this action was performed */ }; +typedef struct { + size_t pos; /* position in bytes from start of file */ + size_t lineno; /* line number in file i.e. number of '\n' in [0, pos) */ +} LineCache; + /* The main struct holding all information of a given file */ struct Editor { Buffer buf; /* original mmap(2)-ed file content at the time of load operation */ @@ -97,6 +101,7 @@ struct Editor { const char *filename; /* filename of which data was loaded */ struct stat info; /* stat as proped on load time */ int fd; /* the file descriptor of the original mmap-ed data */ + LineCache lines; /* mapping between absolute pos in bytes and logical line breaks */ }; /* buffer management */ @@ -128,6 +133,10 @@ static Action *action_alloc(Editor *ed); static void action_free(Action *a); static void action_push(Action **stack, Action *action); static Action *action_pop(Action **stack); +/* logical line counting cache */ +static void lineno_cache_invalidate(LineCache *cache); +static size_t lines_skip_forward(Editor *ed, size_t pos, size_t lines); +static size_t lines_count(Editor *ed, size_t pos, size_t len); /* allocate a new buffer of MAX(size, BUFFER_SIZE) bytes */ static Buffer *buffer_alloc(Editor *ed, size_t size) { @@ -456,6 +465,9 @@ static void change_free(Change *c) { bool editor_insert_raw(Editor *ed, size_t pos, const char *data, size_t len) { if (pos > ed->size) return false; + if (pos < ed->lines.pos) + lineno_cache_invalidate(&ed->lines); + Location loc = piece_get(ed, pos); Piece *p = loc.piece; size_t off = loc.off; @@ -586,8 +598,9 @@ Editor *editor_load(const char *filename) { ed->piece_count = 2; piece_init(&ed->begin, NULL, &ed->end, NULL, 0); piece_init(&ed->end, &ed->begin, NULL, NULL, 0); + lineno_cache_invalidate(&ed->lines); if (filename) { - ed->filename = filename; + ed->filename = strdup(filename); ed->fd = open(filename, O_RDONLY); if (ed->fd == -1) goto out; @@ -652,6 +665,8 @@ bool editor_delete(Editor *ed, size_t pos, size_t len) { return true; if (pos + len > ed->size) return false; + if (pos < ed->lines.pos) + lineno_cache_invalidate(&ed->lines); Location loc = piece_get(ed, pos); Piece *p = loc.piece; size_t off = loc.off; @@ -757,6 +772,7 @@ void editor_free(Editor *ed) { if (ed->buf.data) munmap(ed->buf.data, ed->buf.size); + free((char*)ed->filename); free(ed); } @@ -883,3 +899,97 @@ size_t editor_bytes_get(Editor *ed, size_t pos, size_t len, char *buf) { size_t editor_size(Editor *ed) { return ed->size; } + +/* count the number of new lines '\n' in range [pos, pos+len) */ +static size_t lines_count(Editor *ed, size_t pos, size_t len) { + size_t lines = 0; + editor_iterate(ed, it, pos) { + const char *start = it.text; + while (len > 0 && start < it.end) { + size_t n = MIN(len, (size_t)(it.end - start)); + const char *end = memchr(start, '\n', n); + if (!end) { + len -= n; + break; + } + lines++; + len -= end - start + 1; + start = end + 1; + } + + if (len == 0) + break; + } + return lines; +} + +/* skip n lines forward and return position afterwards */ +static size_t lines_skip_forward(Editor *ed, size_t pos, size_t lines) { + editor_iterate(ed, it, pos) { + const char *start = it.text; + while (lines > 0 && start < it.end) { + size_t n = it.end - start; + const char *end = memchr(start, '\n', n); + if (!end) { + pos += n; + break; + } + pos += end - start + 1; + start = end + 1; + lines--; + } + + if (lines == 0) { + if (start < it.end && *start == '\r') + pos++; + break; + } + } + return pos; +} + +static void lineno_cache_invalidate(LineCache *cache) { + cache->pos = 0; + cache->lineno = 1; +} + +size_t editor_pos_by_lineno(Editor *ed, size_t lineno) { + LineCache *cache = &ed->lines; + if (lineno <= 1) + return 0; + if (lineno > cache->lineno) { + cache->pos = lines_skip_forward(ed, cache->pos, lineno - cache->lineno); + } else if (lineno < cache->lineno) { + #if 0 + // TODO does it make sense to scan memory backwards here? + size_t diff = cache->lineno - lineno; + if (diff < lineno) { + lines_skip_backward(ed, cache->pos, diff); + } else + #endif + cache->pos = lines_skip_forward(ed, 0, lineno - 1); + } + cache->lineno = lineno; + return cache->pos; +} + +size_t editor_lineno_by_pos(Editor *ed, size_t pos) { + LineCache *cache = &ed->lines; + if (pos > ed->size) + pos = ed->size; + if (pos < cache->pos) { + size_t diff = cache->pos - pos; + if (diff < pos) + cache->lineno -= lines_count(ed, pos, diff); + else + cache->lineno = lines_count(ed, 0, pos) + 1; + } else if (pos > cache->pos) { + cache->lineno += lines_count(ed, cache->pos, pos - cache->pos); + } + cache->pos = pos; + return cache->lineno; +} + +const char *editor_filename(Editor *ed) { + return ed->filename; +} |