From 9ec5a4752523fe4aa45cc19557370ad8b180d046 Mon Sep 17 00:00:00 2001 From: Leo Tenenbaum Date: Sat, 19 Dec 2020 00:03:33 -0500 Subject: better errors, saving --- buffer.c | 182 ++++++++++++++++++++++++++++++++++++++++++--------------------- main.c | 17 +++--- test.txt | 6 ++- 3 files changed, 134 insertions(+), 71 deletions(-) diff --git a/buffer.c b/buffer.c index 2656b89..2338427 100644 --- a/buffer.c +++ b/buffer.c @@ -18,15 +18,16 @@ typedef struct { } Line; typedef struct { + char const *filename; double scroll_x, scroll_y; // number of characters scrolled in the x/y direction Font *font; BufferPos cursor_pos; u8 tab_width; - bool out_of_mem; // set to true if an allocation fails float x1, y1, x2, y2; u32 nlines; u32 lines_capacity; Line *lines; + char error[128]; } TextBuffer; // for debugging @@ -54,6 +55,24 @@ void buffer_create(TextBuffer *buffer, Font *font) { buffer->tab_width = 4; } +// this is a macro so we get -Wformat warnings +#define buffer_seterr(buffer, fmt, ...) \ + snprintf(buffer->error, sizeof buffer->error - 1, fmt, ##__VA_ARGS__) + +bool buffer_haserr(TextBuffer *buffer) { + return buffer->error[0] != '\0'; +} + +// returns the buffer's last error +char const *buffer_geterr(TextBuffer *buffer) { + return buffer->error; +} + +// set the buffer's error to indicate that we're out of memory +static void buffer_out_of_mem(TextBuffer *buffer) { + buffer_seterr(buffer, "Out of memory."); +} + // grow capacity of line to at least minimum_capacity // returns true if allocation was succesful static Status buffer_line_grow(TextBuffer *buffer, Line *line, u32 minimum_capacity) { @@ -61,15 +80,14 @@ static Status buffer_line_grow(TextBuffer *buffer, Line *line, u32 minimum_capac // double capacity of line u32 new_capacity = line->capacity == 0 ? 4 : line->capacity * 2; if (new_capacity < line->capacity) { - // overflow. this could only happen with an extremely long line, so we - // treat it as - buffer->out_of_mem = true; + // this could only happen if line->capacity * 2 overflows. + buffer_seterr(buffer, "Line %td is too large.", line - buffer->lines); return false; } char32_t *new_str = realloc(line->str, new_capacity * sizeof *line->str); if (!new_str) { // allocation failed ): - buffer->out_of_mem = true; + buffer_out_of_mem(buffer); return false; } // allocation successful @@ -92,7 +110,7 @@ static Status buffer_lines_grow(TextBuffer *buffer, u32 minimum_capacity) { // zero new lines memset(buffer->lines + buffer->nlines, 0, (new_capacity - buffer->nlines) * sizeof *buffer->lines); } else { - buffer->out_of_mem = true; + buffer_out_of_mem(buffer); return false; } } @@ -110,79 +128,121 @@ static void buffer_line_free(Line *line) { // Does not free the pointer `buffer` (buffer might not have even been allocated with malloc) void buffer_free(TextBuffer *buffer) { + Line *lines = buffer->lines; u32 nlines = buffer->nlines; for (u32 i = 0; i < nlines; ++i) { buffer_line_free(&lines[i]); } free(lines); - buffer->nlines = 0; - buffer->lines = NULL; + + // zero buffer, except for error + char error[sizeof buffer->error]; + memcpy(error, buffer->error, sizeof error); + memset(buffer, 0, sizeof *buffer); + memcpy(buffer->error, error, sizeof error); } -// fp should be a binary file -Status buffer_load_file(TextBuffer *buffer, FILE *fp) { - assert(fp); - fseek(fp, 0, SEEK_END); - size_t file_size = (size_t)ftell(fp); - fseek(fp, 0, SEEK_SET); - if (file_size > 10L<<20) { - // @EVENTUALLY: better handling - printf("File too big.\n"); - return false; - } +// filename must be around for at least as long as the buffer is. +Status buffer_load_file(TextBuffer *buffer, char const *filename) { + buffer->filename = filename; + FILE *fp = fopen(filename, "rb"); + if (fp) { + fseek(fp, 0, SEEK_END); + size_t file_size = (size_t)ftell(fp); + fseek(fp, 0, SEEK_SET); + if (file_size > 10L<<20) { + buffer_seterr(buffer, "File too big (size: %zu).", file_size); + return false; + } - u8 *file_contents = malloc(file_size); - bool success = true; - if (file_contents) { - buffer->lines_capacity = 4; - buffer->lines = calloc(buffer->lines_capacity, sizeof *buffer->lines); // initial lines - buffer->nlines = 1; - size_t bytes_read = fread(file_contents, 1, file_size, fp); - if (bytes_read == file_size) { - char32_t c = 0; - mbstate_t mbstate = {0}; - for (u8 *p = file_contents, *end = p + file_size; p != end; ) { - if (*p == '\r' && p != end-1 && p[1] == '\n') { - // CRLF line endings - p += 2; - c = U'\n'; - } else { - size_t n = mbrtoc32(&c, (char *)p, (size_t)(end - p), &mbstate); - if (n == 0) { - // null character - c = 0; - ++p; - } else if (n == (size_t)(-3)) { - // no bytes consumed, but a character was produced - } else if (n == (size_t)(-2) || n == (size_t)(-1)) { - // incomplete character at end of file or invalid UTF-8 respectively; just treat it as a byte - c = *p; - ++p; + u8 *file_contents = malloc(file_size); + bool success = true; + if (file_contents) { + buffer->lines_capacity = 4; + buffer->lines = calloc(buffer->lines_capacity, sizeof *buffer->lines); // initial lines + buffer->nlines = 1; + size_t bytes_read = fread(file_contents, 1, file_size, fp); + if (bytes_read == file_size) { + char32_t c = 0; + mbstate_t mbstate = {0}; + for (u8 *p = file_contents, *end = p + file_size; p != end; ) { + if (*p == '\r' && p != end-1 && p[1] == '\n') { + // CRLF line endings + p += 2; + c = U'\n'; } else { - p += n; + size_t n = mbrtoc32(&c, (char *)p, (size_t)(end - p), &mbstate); + if (n == 0) { + // null character + c = 0; + ++p; + } else if (n == (size_t)(-3)) { + // no bytes consumed, but a character was produced + } else if (n == (size_t)(-2) || n == (size_t)(-1)) { + // incomplete character at end of file or invalid UTF-8 respectively; fail + success = false; + buffer_seterr(buffer, "Invalid UTF-8 (position: %td).", p - file_contents); + break; + } else { + p += n; + } } - } - if (c == U'\n') { - if (buffer_lines_grow(buffer, buffer->nlines + 1)) - ++buffer->nlines; - } else { - u32 line_idx = buffer->nlines - 1; - Line *line = &buffer->lines[line_idx]; + if (c == U'\n') { + if (buffer_lines_grow(buffer, buffer->nlines + 1)) + ++buffer->nlines; + } else { + u32 line_idx = buffer->nlines - 1; + Line *line = &buffer->lines[line_idx]; - buffer_line_append_char(buffer, line, c); + buffer_line_append_char(buffer, line, c); + } } } + free(file_contents); } - free(file_contents); - } - if (ferror(fp)) success = false; - if (!success) { - buffer_free(buffer); + if (ferror(fp)) { + buffer_seterr(buffer, "Error reading from file."); + success = false; + } + if (fclose(fp) != 0) { + buffer_seterr(buffer, "Error closing file."); + success = false; + } + if (!success) { + buffer_free(buffer); + } + return success; + } else { + buffer_seterr(buffer, "File %s does not exist.", filename); + return false; } - return success; +} + +Status buffer_save(TextBuffer *buffer) { + FILE *out = fopen(buffer->filename, "wb"); + if (out) { + bool success = true; + for (Line *line = buffer->lines, *end = line + buffer->nlines; line != end; ++line) { + mbstate_t state = {0}; + for (char32_t *p = line->str, *p_end = p + line->len; p != p_end; ++p) { + char utf8[MB_LEN_MAX] = {0}; + size_t bytes = c32rtomb(utf8, *p, &state); + fwrite(utf8, 1, bytes, out); + } + if (line != end-1) { + putc('\n', out); + } + } + if (ferror(out)) success = false; + if (fclose(out) != 0) success = false; + return success; + } else { + buffer_seterr(buffer, "Couldn't create file %s.", buffer->filename); + return false; + } } // print the contents of a buffer to stdout diff --git a/main.c b/main.c index 8f40828..93bac8a 100644 --- a/main.c +++ b/main.c @@ -68,14 +68,8 @@ int main(void) { TextBuffer text_buffer; buffer_create(&text_buffer, font); - { - FILE *fp = fopen("test.txt", "rb"); - assert(fp); - bool success = buffer_load_file(&text_buffer, fp); - fclose(fp); - if (!success) - die("Error loading file."); - } + if (!buffer_load_file(&text_buffer, "test.txt")) + die("Error loading file: %s", buffer_geterr(&text_buffer)); Uint32 time_at_last_frame = SDL_GetTicks(); @@ -141,6 +135,13 @@ int main(void) { else buffer_backspace_at_cursor(&text_buffer, 1); break; + case SDLK_s: + if (ctrl) { + if (!buffer_save(&text_buffer)) { + printf("Error saving: %s.", buffer_geterr(&text_buffer)); + } + } + break; } } break; case SDL_TEXTINPUT: { diff --git a/test.txt b/test.txt index b5d2be8..306195f 100644 --- a/test.txt +++ b/test.txt @@ -1,3 +1,5 @@ -12 33 100 4 -7 66 2 88 +3 33 100 4 +7 1 2 88 3 33 333 3333 +100 49 388 101 +N/A 1 N/A N/A \ No newline at end of file -- cgit v1.2.3