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#include "undo.h"
#include "string.h"
#include "vec.h"
#include <stdio.h>
#include <stdlib.h>
void undo_init(struct undo_stack *undo, uint32_t initial_capacity) {
undo->top = INVALID_TOP;
undo->undo_in_progress = false;
VEC_INIT(&undo->records, initial_capacity);
}
void undo_clear(struct undo_stack *undo) {
undo->top = INVALID_TOP;
VEC_CLEAR(&undo->records);
}
void undo_destroy(struct undo_stack *undo) {
VEC_FOR_EACH(&undo->records, struct undo_record * rec) {
if (rec->type == Undo_Delete && rec->data.delete.data != NULL &&
rec->data.delete.nbytes > 0) {
free(rec->data.delete.data);
}
}
undo_clear(undo);
VEC_DESTROY(&undo->records);
}
uint32_t undo_push_boundary(struct undo_stack *undo,
struct undo_boundary boundary) {
// we can only have one save point
if (boundary.save_point) {
VEC_FOR_EACH(&undo->records, struct undo_record * rec) {
if (rec->type == Undo_Boundary && rec->data.boundary.save_point) {
rec->data.boundary.save_point = false;
}
}
}
VEC_APPEND(&undo->records, struct undo_record * rec);
rec->type = Undo_Boundary;
rec->data.boundary = boundary;
if (!undo->undo_in_progress) {
undo->top = VEC_SIZE(&undo->records) - 1;
}
return VEC_SIZE(&undo->records) - 1;
}
bool pos_equal(struct position *a, struct position *b) {
return a->row == b->row && a->col == b->col;
}
uint32_t undo_push_add(struct undo_stack *undo, struct undo_add add) {
// "compress"
if (!VEC_EMPTY(&undo->records) &&
VEC_BACK(&undo->records)->type == Undo_Add &&
pos_equal(&VEC_BACK(&undo->records)->data.add.end, &add.begin)) {
VEC_BACK(&undo->records)->data.add.end = add.end;
} else {
VEC_APPEND(&undo->records, struct undo_record * rec);
rec->type = Undo_Add;
rec->data.add = add;
}
if (!undo->undo_in_progress) {
undo->top = VEC_SIZE(&undo->records) - 1;
}
return VEC_SIZE(&undo->records) - 1;
}
uint32_t undo_push_delete(struct undo_stack *undo, struct undo_delete delete) {
VEC_APPEND(&undo->records, struct undo_record * rec);
rec->type = Undo_Delete;
rec->data.delete = delete;
if (!undo->undo_in_progress) {
undo->top = VEC_SIZE(&undo->records) - 1;
}
return VEC_SIZE(&undo->records) - 1;
}
void undo_begin(struct undo_stack *undo) { undo->undo_in_progress = true; }
void undo_next(struct undo_stack *undo, struct undo_record **records_out,
uint32_t *nrecords_out) {
*nrecords_out = 0;
*records_out = NULL;
if (VEC_EMPTY(&undo->records)) {
return;
}
if (undo->top == INVALID_TOP) {
// reset back to the top (redo)
undo->top = VEC_SIZE(&undo->records) - 1;
}
uint32_t nrecords = 1;
struct undo_record *current = &VEC_ENTRIES(&undo->records)[undo->top];
// skip any leading boundaries
while (undo->top > 0 && current->type == Undo_Boundary) {
++nrecords;
--undo->top;
current = &VEC_ENTRIES(&undo->records)[undo->top];
}
// find the next boundary
while (undo->top > 0 && current->type != Undo_Boundary) {
++nrecords;
--undo->top;
current = &VEC_ENTRIES(&undo->records)[undo->top];
}
if (nrecords > 0) {
*records_out = calloc(nrecords, sizeof(struct undo_record));
*nrecords_out = nrecords;
struct undo_record *dest = *records_out;
// copy backwards
for (uint32_t reci = undo->top + nrecords, outi = 0; reci > undo->top;
--reci, ++outi) {
dest[outi] = VEC_ENTRIES(&undo->records)[reci - 1];
}
}
if (undo->top > 0) {
--undo->top;
} else {
undo->top = INVALID_TOP;
}
}
void undo_end(struct undo_stack *undo) { undo->undo_in_progress = false; }
uint32_t undo_size(struct undo_stack *undo) { return VEC_SIZE(&undo->records); }
uint32_t undo_current_position(struct undo_stack *undo) { return undo->top; }
size_t rec_to_str(struct undo_record *rec, char *buffer, size_t n) {
switch (rec->type) {
case Undo_Add:
return snprintf(buffer, n, "add { begin: (%d, %d) end: (%d, %d)}",
rec->data.add.begin.row, rec->data.add.begin.col,
rec->data.add.end.row, rec->data.add.end.col);
case Undo_Delete:
return snprintf(buffer, n, "delete { pos: (%d, %d), ptr: 0x%p, nbytes: %d}",
rec->data.delete.pos.row, rec->data.delete.pos.col,
(void *)rec->data.delete.data, rec->data.delete.nbytes);
default:
return snprintf(buffer, n, "boundary { save_point: %s }",
rec->data.boundary.save_point ? "yes" : "no");
}
}
const char *undo_dump(struct undo_stack *undo) {
uint32_t left = 8192;
const char *buf = malloc(left);
char *pos = (char *)buf;
pos[0] = '\0';
char rec_buf[256];
VEC_FOR_EACH_INDEXED(&undo->records, struct undo_record * rec, reci) {
rec_to_str(rec, rec_buf, 256);
uint32_t written = snprintf(pos, left, "%d: [%s]%s\n", reci, rec_buf,
reci == undo->top ? " <- top" : "");
left = written > left ? 0 : left - written;
pos += written;
}
return buf;
}
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