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-rw-r--r--src/dged/text.c496
1 files changed, 496 insertions, 0 deletions
diff --git a/src/dged/text.c b/src/dged/text.c
new file mode 100644
index 0000000..f8ba72d
--- /dev/null
+++ b/src/dged/text.c
@@ -0,0 +1,496 @@
+#include "text.h"
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "display.h"
+#include "signal.h"
+#include "utf8.h"
+
+enum flags {
+ LineChanged = 1 << 0,
+};
+
+struct line {
+ uint8_t *data;
+ uint8_t flags;
+ uint32_t nbytes;
+ uint32_t nchars;
+};
+
+struct text {
+ // raw bytes without any null terminators
+ struct line *lines;
+ uint32_t nlines;
+ uint32_t capacity;
+};
+
+struct text *text_create(uint32_t initial_capacity) {
+ struct text *txt = calloc(1, sizeof(struct text));
+ txt->lines = calloc(initial_capacity, sizeof(struct line));
+ txt->capacity = initial_capacity;
+ txt->nlines = 0;
+
+ return txt;
+}
+
+void text_destroy(struct text *text) {
+ for (uint32_t li = 0; li < text->nlines; ++li) {
+ free(text->lines[li].data);
+ text->lines[li].data = NULL;
+ text->lines[li].flags = 0;
+ text->lines[li].nbytes = 0;
+ text->lines[li].nchars = 0;
+ }
+
+ free(text->lines);
+
+ free(text);
+}
+
+void text_clear(struct text *text) {
+ for (uint32_t li = 0; li < text->nlines; ++li) {
+ free(text->lines[li].data);
+ text->lines[li].data = NULL;
+ text->lines[li].flags = 0;
+ text->lines[li].nbytes = 0;
+ text->lines[li].nchars = 0;
+ }
+
+ text->nlines = 0;
+}
+
+// given `char_idx` as a character index, return the byte index
+uint32_t charidx_to_byteidx(struct line *line, uint32_t char_idx) {
+ if (char_idx > line->nchars) {
+ return line->nbytes;
+ }
+ return utf8_nbytes(line->data, line->nbytes, char_idx);
+}
+
+uint32_t text_col_to_byteindex(struct text *text, uint32_t line, uint32_t col) {
+ return charidx_to_byteidx(&text->lines[line], col);
+}
+
+// given `byte_idx` as a byte index, return the character index
+uint32_t byteidx_to_charidx(struct line *line, uint32_t byte_idx) {
+ if (byte_idx > line->nbytes) {
+ return line->nchars;
+ }
+
+ return utf8_nchars(line->data, byte_idx);
+}
+
+uint32_t text_byteindex_to_col(struct text *text, uint32_t line,
+ uint32_t byteindex) {
+ return byteidx_to_charidx(&text->lines[line], byteindex);
+}
+
+void append_empty_lines(struct text *text, uint32_t numlines) {
+
+ if (text->nlines + numlines >= text->capacity) {
+ text->capacity += text->capacity + numlines > text->capacity * 2
+ ? numlines + 1
+ : text->capacity;
+ text->lines = realloc(text->lines, sizeof(struct line) * text->capacity);
+ }
+
+ for (uint32_t i = 0; i < numlines; ++i) {
+ struct line *nline = &text->lines[text->nlines];
+ nline->data = NULL;
+ nline->nbytes = 0;
+ nline->nchars = 0;
+ nline->flags = 0;
+
+ ++text->nlines;
+ }
+
+ if (text->nlines > text->capacity) {
+ printf("text->nlines: %d, text->capacity: %d\n", text->nlines,
+ text->capacity);
+ raise(SIGTRAP);
+ }
+}
+
+void ensure_line(struct text *text, uint32_t line) {
+ if (line >= text->nlines) {
+ append_empty_lines(text, line - text->nlines + 1);
+ }
+}
+
+// It is assumed that `data` does not contain any \n, that is handled by
+// higher-level functions
+void insert_at(struct text *text, uint32_t line, uint32_t col, uint8_t *data,
+ uint32_t len, uint32_t nchars) {
+
+ if (len == 0) {
+ return;
+ }
+
+ ensure_line(text, line);
+
+ struct line *l = &text->lines[line];
+
+ l->nbytes += len;
+ l->nchars += nchars;
+ l->flags = LineChanged;
+ l->data = realloc(l->data, l->nbytes);
+
+ uint32_t bytei = charidx_to_byteidx(l, col);
+
+ // move following bytes out of the way
+ if (bytei + len < l->nbytes) {
+ uint32_t start = bytei + len;
+ memmove(l->data + start, l->data + bytei, l->nbytes - start);
+ }
+
+ // insert new chars
+ memcpy(l->data + bytei, data, len);
+}
+
+uint32_t text_line_length(struct text *text, uint32_t lineidx) {
+ return text->lines[lineidx].nchars;
+}
+
+uint32_t text_line_size(struct text *text, uint32_t lineidx) {
+ return text->lines[lineidx].nbytes;
+}
+
+uint32_t text_num_lines(struct text *text) { return text->nlines; }
+
+void split_line(uint32_t col, struct line *line, struct line *next) {
+ uint8_t *data = line->data;
+ uint32_t nbytes = line->nbytes;
+ uint32_t nchars = line->nchars;
+
+ uint32_t chari = col;
+ uint32_t bytei = charidx_to_byteidx(line, chari);
+
+ line->nbytes = bytei;
+ line->nchars = chari;
+ next->nbytes = nbytes - bytei;
+ next->nchars = nchars - chari;
+ line->flags = next->flags = line->flags;
+
+ next->data = NULL;
+ line->data = NULL;
+
+ // first, handle some cases where the new line or the pre-existing one is
+ // empty
+ if (next->nbytes == 0) {
+ line->data = data;
+ } else if (line->nbytes == 0) {
+ next->data = data;
+ } else {
+ // actually split the line
+ next->data = (uint8_t *)realloc(next->data, next->nbytes);
+ memcpy(next->data, data + bytei, next->nbytes);
+
+ line->data = (uint8_t *)realloc(line->data, line->nbytes);
+ memcpy(line->data, data, line->nbytes);
+
+ free(data);
+ }
+}
+
+void mark_lines_changed(struct text *text, uint32_t line, uint32_t nlines) {
+ for (uint32_t linei = line; linei < (line + nlines); ++linei) {
+ text->lines[linei].flags |= LineChanged;
+ }
+}
+
+void shift_lines(struct text *text, uint32_t start, int32_t direction) {
+ struct line *dest = &text->lines[((int64_t)start + direction)];
+ struct line *src = &text->lines[start];
+ uint32_t nlines = text->nlines - (dest > src ? (start + direction) : start);
+ memmove(dest, src, nlines * sizeof(struct line));
+}
+
+void new_line_at(struct text *text, uint32_t line, uint32_t col) {
+ ensure_line(text, line);
+
+ uint32_t newline = line + 1;
+ append_empty_lines(text, 1);
+
+ mark_lines_changed(text, line, text->nlines - line);
+
+ // move following lines out of the way, if there are any
+ if (newline + 1 < text->nlines) {
+ shift_lines(text, newline, 1);
+ }
+
+ // split line if needed
+ split_line(col, &text->lines[line], &text->lines[newline]);
+}
+
+void delete_line(struct text *text, uint32_t line) {
+ if (text->nlines == 0) {
+ return;
+ }
+
+ mark_lines_changed(text, line, text->nlines - line);
+
+ free(text->lines[line].data);
+ text->lines[line].data = NULL;
+
+ if (line + 1 < text->nlines) {
+ shift_lines(text, line + 1, -1);
+ }
+
+ --text->nlines;
+ text->lines[text->nlines].data = NULL;
+ text->lines[text->nlines].nbytes = 0;
+ text->lines[text->nlines].nchars = 0;
+}
+
+void text_insert_at_inner(struct text *text, uint32_t line, uint32_t col,
+ uint8_t *bytes, uint32_t nbytes,
+ uint32_t *lines_added, uint32_t *cols_added,
+ bool force_newline) {
+ uint32_t linelen = 0, start_line = line;
+
+ *cols_added = 0;
+ for (uint32_t bytei = 0; bytei < nbytes; ++bytei) {
+ uint8_t byte = bytes[bytei];
+ if (byte == '\n') {
+ uint8_t *line_data = bytes + (bytei - linelen);
+ uint32_t nchars = utf8_nchars(line_data, linelen);
+
+ insert_at(text, line, col, line_data, linelen, nchars);
+
+ col += nchars;
+
+ // only insert a newline if we have to
+ if (force_newline || linelen == 0 || col < text_line_length(text, line) ||
+ line + 1 < text->nlines) {
+ new_line_at(text, line, col);
+ }
+
+ ++line;
+ linelen = 0;
+ col = 0;
+ } else {
+ ++linelen;
+ }
+ }
+
+ // handle remaining
+ if (linelen > 0) {
+ uint8_t *line_data = bytes + (nbytes - linelen);
+ uint32_t nchars = utf8_nchars(line_data, linelen);
+ insert_at(text, line, col, line_data, linelen, nchars);
+ *cols_added = nchars;
+ }
+
+ *lines_added = line - start_line;
+}
+
+void text_append(struct text *text, uint8_t *bytes, uint32_t nbytes,
+ uint32_t *lines_added, uint32_t *cols_added) {
+ uint32_t line = text->nlines > 0 ? text->nlines - 1 : 0;
+ uint32_t col = text_line_length(text, line);
+
+ text_insert_at_inner(text, line, col, bytes, nbytes, lines_added, cols_added,
+ true);
+}
+
+void text_insert_at(struct text *text, uint32_t line, uint32_t col,
+ uint8_t *bytes, uint32_t nbytes, uint32_t *lines_added,
+ uint32_t *cols_added) {
+ text_insert_at_inner(text, line, col, bytes, nbytes, lines_added, cols_added,
+ false);
+}
+
+void text_delete(struct text *text, uint32_t start_line, uint32_t start_col,
+ uint32_t end_line, uint32_t end_col) {
+
+ if (text->nlines == 0) {
+ return;
+ }
+
+ uint32_t maxline = text->nlines > 0 ? text->nlines - 1 : 0;
+
+ // make sure we stay inside
+ if (start_line > maxline) {
+ start_line = maxline;
+ start_col = text->lines[start_line].nchars > 0
+ ? text->lines[start_line].nchars - 1
+ : 0;
+ }
+
+ if (end_line > maxline) {
+ end_line = maxline;
+ end_col = text->lines[end_line].nchars;
+ }
+
+ struct line *firstline = &text->lines[start_line];
+ struct line *lastline = &text->lines[end_line];
+
+ // clamp column
+ if (start_col > firstline->nchars) {
+ start_col = firstline->nchars > 0 ? firstline->nchars - 1 : 0;
+ }
+
+ // handle deletion of newlines
+ if (end_col > lastline->nchars) {
+ if (end_line + 1 < text->nlines) {
+ end_col = 0;
+ ++end_line;
+ lastline = &text->lines[end_line];
+ } else {
+ end_col = lastline->nchars;
+ }
+ }
+
+ uint32_t bytei = utf8_nbytes(lastline->data, lastline->nbytes, end_col);
+ if (lastline == firstline) {
+ // in this case we can "overwrite"
+ uint32_t dstbytei =
+ utf8_nbytes(firstline->data, firstline->nbytes, start_col);
+ memcpy(firstline->data + dstbytei, lastline->data + bytei,
+ lastline->nbytes - bytei);
+ } else {
+ // otherwise we actually have to copy from the last line
+ insert_at(text, start_line, start_col, lastline->data + bytei,
+ lastline->nbytes - bytei, lastline->nchars - end_col);
+ }
+
+ firstline->nchars = start_col + (lastline->nchars - end_col);
+ firstline->nbytes =
+ utf8_nbytes(firstline->data, firstline->nbytes, start_col) +
+ (lastline->nbytes - bytei);
+
+ // delete full lines, backwards to not shift old, crappy data upwards
+ for (uint32_t linei = end_line >= text->nlines ? end_line - 1 : end_line;
+ linei > start_line; --linei) {
+ delete_line(text, linei);
+ }
+
+ // if this is the last line in the buffer, and it turns out empty, remove it
+ if (firstline->nbytes == 0 && start_line == text->nlines - 1) {
+ delete_line(text, start_line);
+ }
+}
+
+void text_for_each_chunk(struct text *text, chunk_cb callback, void *userdata) {
+ // if representation of text is changed, this can be changed as well
+ text_for_each_line(text, 0, text->nlines, callback, userdata);
+}
+
+void text_for_each_line(struct text *text, uint32_t line, uint32_t nlines,
+ chunk_cb callback, void *userdata) {
+ uint32_t nlines_max =
+ (line + nlines) > text->nlines ? text->nlines : (line + nlines);
+ for (uint32_t li = line; li < nlines_max; ++li) {
+ struct line *src_line = &text->lines[li];
+ struct text_chunk line = (struct text_chunk){
+ .text = src_line->data,
+ .nbytes = src_line->nbytes,
+ .nchars = src_line->nchars,
+ .line = li,
+ };
+ callback(&line, userdata);
+ }
+}
+
+struct text_chunk text_get_line(struct text *text, uint32_t line) {
+ struct line *src_line = &text->lines[line];
+ return (struct text_chunk){
+ .text = src_line->data,
+ .nbytes = src_line->nbytes,
+ .nchars = src_line->nchars,
+ .line = line,
+ };
+}
+
+struct copy_cmd {
+ uint32_t line;
+ uint32_t byteoffset;
+ uint32_t nbytes;
+};
+
+struct text_chunk text_get_region(struct text *text, uint32_t start_line,
+ uint32_t start_col, uint32_t end_line,
+ uint32_t end_col) {
+ if (start_line == end_line && start_col == end_col) {
+ return (struct text_chunk){0};
+ }
+
+ struct line *first_line = &text->lines[start_line];
+ struct line *last_line = &text->lines[end_line];
+
+ if (start_col > first_line->nchars) {
+ return (struct text_chunk){0};
+ }
+
+ // handle copying of newlines
+ if (end_col > last_line->nchars) {
+ ++end_line;
+ end_col = 0;
+ last_line = &text->lines[end_line];
+ }
+
+ uint32_t nlines = end_line - start_line + 1;
+ struct copy_cmd *copy_cmds = calloc(nlines, sizeof(struct copy_cmd));
+
+ uint32_t total_chars = 0, total_bytes = 0;
+ for (uint32_t line = start_line; line <= end_line; ++line) {
+ struct line *l = &text->lines[line];
+ total_chars += l->nchars;
+ total_bytes += l->nbytes;
+
+ struct copy_cmd *cmd = &copy_cmds[line - start_line];
+ cmd->line = line;
+ cmd->byteoffset = 0;
+ cmd->nbytes = l->nbytes;
+ }
+
+ // correct first line
+ struct copy_cmd *cmd_first = &copy_cmds[0];
+ uint32_t byteoff =
+ utf8_nbytes(first_line->data, first_line->nbytes, start_col);
+ cmd_first->byteoffset += byteoff;
+ cmd_first->nbytes -= byteoff;
+ total_bytes -= byteoff;
+ total_chars -= start_col;
+
+ // correct last line
+ struct copy_cmd *cmd_last = &copy_cmds[nlines - 1];
+ uint32_t byteindex = utf8_nbytes(last_line->data, last_line->nbytes, end_col);
+ cmd_last->nbytes -= (last_line->nbytes - byteindex);
+ total_bytes -= (last_line->nbytes - byteindex);
+ total_chars -= (last_line->nchars - end_col);
+
+ uint8_t *data = (uint8_t *)malloc(
+ total_bytes + /* nr of newline chars */ (end_line - start_line));
+
+ // copy data
+ for (uint32_t cmdi = 0, curr = 0; cmdi < nlines; ++cmdi) {
+ struct copy_cmd *c = &copy_cmds[cmdi];
+ struct line *l = &text->lines[c->line];
+ memcpy(data + curr, l->data + c->byteoffset, c->nbytes);
+ curr += c->nbytes;
+
+ if (cmdi != (nlines - 1)) {
+ data[curr] = '\n';
+ ++curr;
+ ++total_bytes;
+ ++total_chars;
+ }
+ }
+
+ free(copy_cmds);
+ return (struct text_chunk){
+ .text = data,
+ .line = 0,
+ .nbytes = total_bytes,
+ .nchars = total_chars,
+ .allocated = true,
+ };
+}
+
+bool text_line_contains_unicode(struct text *text, uint32_t line) {
+ return text->lines[line].nbytes != text->lines[line].nchars;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-12-06 22:48:52 +0000