| // SPDX-License-Identifier: LGPL-2.1+ |
| /* Copyright (C) 2022 Kent Overstreet */ |
| |
| #include <linux/bitmap.h> |
| #include <linux/err.h> |
| #include <linux/export.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/string_helpers.h> |
| |
| #include "printbuf.h" |
| |
| static inline unsigned printbuf_linelen(struct printbuf *buf) |
| { |
| return buf->pos - buf->last_newline; |
| } |
| |
| int bch2_printbuf_make_room(struct printbuf *out, unsigned extra) |
| { |
| unsigned new_size; |
| char *buf; |
| |
| if (!out->heap_allocated) |
| return 0; |
| |
| /* Reserved space for terminating nul: */ |
| extra += 1; |
| |
| if (out->pos + extra < out->size) |
| return 0; |
| |
| new_size = roundup_pow_of_two(out->size + extra); |
| |
| /* |
| * Note: output buffer must be freeable with kfree(), it's not required |
| * that the user use printbuf_exit(). |
| */ |
| buf = krealloc(out->buf, new_size, !out->atomic ? GFP_KERNEL : GFP_NOWAIT); |
| |
| if (!buf) { |
| out->allocation_failure = true; |
| return -ENOMEM; |
| } |
| |
| out->buf = buf; |
| out->size = new_size; |
| return 0; |
| } |
| |
| void bch2_prt_vprintf(struct printbuf *out, const char *fmt, va_list args) |
| { |
| int len; |
| |
| do { |
| va_list args2; |
| |
| va_copy(args2, args); |
| len = vsnprintf(out->buf + out->pos, printbuf_remaining(out), fmt, args2); |
| } while (len + 1 >= printbuf_remaining(out) && |
| !bch2_printbuf_make_room(out, len + 1)); |
| |
| len = min_t(size_t, len, |
| printbuf_remaining(out) ? printbuf_remaining(out) - 1 : 0); |
| out->pos += len; |
| } |
| |
| void bch2_prt_printf(struct printbuf *out, const char *fmt, ...) |
| { |
| va_list args; |
| int len; |
| |
| do { |
| va_start(args, fmt); |
| len = vsnprintf(out->buf + out->pos, printbuf_remaining(out), fmt, args); |
| va_end(args); |
| } while (len + 1 >= printbuf_remaining(out) && |
| !bch2_printbuf_make_room(out, len + 1)); |
| |
| len = min_t(size_t, len, |
| printbuf_remaining(out) ? printbuf_remaining(out) - 1 : 0); |
| out->pos += len; |
| } |
| |
| /** |
| * bch2_printbuf_str() - returns printbuf's buf as a C string, guaranteed to be |
| * null terminated |
| * @buf: printbuf to terminate |
| * Returns: Printbuf contents, as a nul terminated C string |
| */ |
| const char *bch2_printbuf_str(const struct printbuf *buf) |
| { |
| /* |
| * If we've written to a printbuf then it's guaranteed to be a null |
| * terminated string - but if we haven't, then we might not have |
| * allocated a buffer at all: |
| */ |
| return buf->pos |
| ? buf->buf |
| : ""; |
| } |
| |
| /** |
| * bch2_printbuf_exit() - exit a printbuf, freeing memory it owns and poisoning it |
| * against accidental use. |
| * @buf: printbuf to exit |
| */ |
| void bch2_printbuf_exit(struct printbuf *buf) |
| { |
| if (buf->heap_allocated) { |
| kfree(buf->buf); |
| buf->buf = ERR_PTR(-EINTR); /* poison value */ |
| } |
| } |
| |
| void bch2_printbuf_tabstops_reset(struct printbuf *buf) |
| { |
| buf->nr_tabstops = 0; |
| } |
| |
| void bch2_printbuf_tabstop_pop(struct printbuf *buf) |
| { |
| if (buf->nr_tabstops) |
| --buf->nr_tabstops; |
| } |
| |
| /* |
| * bch2_printbuf_tabstop_set() - add a tabstop, n spaces from the previous tabstop |
| * |
| * @buf: printbuf to control |
| * @spaces: number of spaces from previous tabpstop |
| * |
| * In the future this function may allocate memory if setting more than |
| * PRINTBUF_INLINE_TABSTOPS or setting tabstops more than 255 spaces from start |
| * of line. |
| */ |
| int bch2_printbuf_tabstop_push(struct printbuf *buf, unsigned spaces) |
| { |
| unsigned prev_tabstop = buf->nr_tabstops |
| ? buf->_tabstops[buf->nr_tabstops - 1] |
| : 0; |
| |
| if (WARN_ON(buf->nr_tabstops >= ARRAY_SIZE(buf->_tabstops))) |
| return -EINVAL; |
| |
| buf->_tabstops[buf->nr_tabstops++] = prev_tabstop + spaces; |
| buf->has_indent_or_tabstops = true; |
| return 0; |
| } |
| |
| /** |
| * bch2_printbuf_indent_add() - add to the current indent level |
| * |
| * @buf: printbuf to control |
| * @spaces: number of spaces to add to the current indent level |
| * |
| * Subsequent lines, and the current line if the output position is at the start |
| * of the current line, will be indented by @spaces more spaces. |
| */ |
| void bch2_printbuf_indent_add(struct printbuf *buf, unsigned spaces) |
| { |
| if (WARN_ON_ONCE(buf->indent + spaces < buf->indent)) |
| spaces = 0; |
| |
| buf->indent += spaces; |
| prt_chars(buf, ' ', spaces); |
| |
| buf->has_indent_or_tabstops = true; |
| } |
| |
| /** |
| * bch2_printbuf_indent_sub() - subtract from the current indent level |
| * |
| * @buf: printbuf to control |
| * @spaces: number of spaces to subtract from the current indent level |
| * |
| * Subsequent lines, and the current line if the output position is at the start |
| * of the current line, will be indented by @spaces less spaces. |
| */ |
| void bch2_printbuf_indent_sub(struct printbuf *buf, unsigned spaces) |
| { |
| if (WARN_ON_ONCE(spaces > buf->indent)) |
| spaces = buf->indent; |
| |
| if (buf->last_newline + buf->indent == buf->pos) { |
| buf->pos -= spaces; |
| printbuf_nul_terminate(buf); |
| } |
| buf->indent -= spaces; |
| |
| if (!buf->indent && !buf->nr_tabstops) |
| buf->has_indent_or_tabstops = false; |
| } |
| |
| void bch2_prt_newline(struct printbuf *buf) |
| { |
| unsigned i; |
| |
| bch2_printbuf_make_room(buf, 1 + buf->indent); |
| |
| __prt_char(buf, '\n'); |
| |
| buf->last_newline = buf->pos; |
| |
| for (i = 0; i < buf->indent; i++) |
| __prt_char(buf, ' '); |
| |
| printbuf_nul_terminate(buf); |
| |
| buf->last_field = buf->pos; |
| buf->cur_tabstop = 0; |
| } |
| |
| /* |
| * Returns spaces from start of line, if set, or 0 if unset: |
| */ |
| static inline unsigned cur_tabstop(struct printbuf *buf) |
| { |
| return buf->cur_tabstop < buf->nr_tabstops |
| ? buf->_tabstops[buf->cur_tabstop] |
| : 0; |
| } |
| |
| static void __prt_tab(struct printbuf *out) |
| { |
| int spaces = max_t(int, 0, cur_tabstop(out) - printbuf_linelen(out)); |
| |
| prt_chars(out, ' ', spaces); |
| |
| out->last_field = out->pos; |
| out->cur_tabstop++; |
| } |
| |
| /** |
| * bch2_prt_tab() - Advance printbuf to the next tabstop |
| * @out: printbuf to control |
| * |
| * Advance output to the next tabstop by printing spaces. |
| */ |
| void bch2_prt_tab(struct printbuf *out) |
| { |
| if (WARN_ON(!cur_tabstop(out))) |
| return; |
| |
| __prt_tab(out); |
| } |
| |
| static void __prt_tab_rjust(struct printbuf *buf) |
| { |
| unsigned move = buf->pos - buf->last_field; |
| int pad = (int) cur_tabstop(buf) - (int) printbuf_linelen(buf); |
| |
| if (pad > 0) { |
| bch2_printbuf_make_room(buf, pad); |
| |
| if (buf->last_field + pad < buf->size) |
| memmove(buf->buf + buf->last_field + pad, |
| buf->buf + buf->last_field, |
| min(move, buf->size - 1 - buf->last_field - pad)); |
| |
| if (buf->last_field < buf->size) |
| memset(buf->buf + buf->last_field, ' ', |
| min((unsigned) pad, buf->size - buf->last_field)); |
| |
| buf->pos += pad; |
| printbuf_nul_terminate(buf); |
| } |
| |
| buf->last_field = buf->pos; |
| buf->cur_tabstop++; |
| } |
| |
| /** |
| * bch2_prt_tab_rjust - Advance printbuf to the next tabstop, right justifying |
| * previous output |
| * |
| * @buf: printbuf to control |
| * |
| * Advance output to the next tabstop by inserting spaces immediately after the |
| * previous tabstop, right justifying previously outputted text. |
| */ |
| void bch2_prt_tab_rjust(struct printbuf *buf) |
| { |
| if (WARN_ON(!cur_tabstop(buf))) |
| return; |
| |
| __prt_tab_rjust(buf); |
| } |
| |
| /** |
| * bch2_prt_bytes_indented() - Print an array of chars, handling embedded control characters |
| * |
| * @out: output printbuf |
| * @str: string to print |
| * @count: number of bytes to print |
| * |
| * The following contol characters are handled as so: |
| * \n: prt_newline newline that obeys current indent level |
| * \t: prt_tab advance to next tabstop |
| * \r: prt_tab_rjust advance to next tabstop, with right justification |
| */ |
| void bch2_prt_bytes_indented(struct printbuf *out, const char *str, unsigned count) |
| { |
| const char *unprinted_start = str; |
| const char *end = str + count; |
| |
| if (!out->has_indent_or_tabstops || out->suppress_indent_tabstop_handling) { |
| prt_bytes(out, str, count); |
| return; |
| } |
| |
| while (str != end) { |
| switch (*str) { |
| case '\n': |
| prt_bytes(out, unprinted_start, str - unprinted_start); |
| unprinted_start = str + 1; |
| bch2_prt_newline(out); |
| break; |
| case '\t': |
| if (likely(cur_tabstop(out))) { |
| prt_bytes(out, unprinted_start, str - unprinted_start); |
| unprinted_start = str + 1; |
| __prt_tab(out); |
| } |
| break; |
| case '\r': |
| if (likely(cur_tabstop(out))) { |
| prt_bytes(out, unprinted_start, str - unprinted_start); |
| unprinted_start = str + 1; |
| __prt_tab_rjust(out); |
| } |
| break; |
| } |
| |
| str++; |
| } |
| |
| prt_bytes(out, unprinted_start, str - unprinted_start); |
| } |
| |
| /** |
| * bch2_prt_human_readable_u64() - Print out a u64 in human readable units |
| * @out: output printbuf |
| * @v: integer to print |
| * |
| * Units of 2^10 (default) or 10^3 are controlled via @out->si_units |
| */ |
| void bch2_prt_human_readable_u64(struct printbuf *out, u64 v) |
| { |
| bch2_printbuf_make_room(out, 10); |
| out->pos += string_get_size(v, 1, !out->si_units, |
| out->buf + out->pos, |
| printbuf_remaining_size(out)); |
| } |
| |
| /** |
| * bch2_prt_human_readable_s64() - Print out a s64 in human readable units |
| * @out: output printbuf |
| * @v: integer to print |
| * |
| * Units of 2^10 (default) or 10^3 are controlled via @out->si_units |
| */ |
| void bch2_prt_human_readable_s64(struct printbuf *out, s64 v) |
| { |
| if (v < 0) |
| prt_char(out, '-'); |
| bch2_prt_human_readable_u64(out, abs(v)); |
| } |
| |
| /** |
| * bch2_prt_units_u64() - Print out a u64 according to printbuf unit options |
| * @out: output printbuf |
| * @v: integer to print |
| * |
| * Units are either raw (default), or human reabable units (controlled via |
| * @buf->human_readable_units) |
| */ |
| void bch2_prt_units_u64(struct printbuf *out, u64 v) |
| { |
| if (out->human_readable_units) |
| bch2_prt_human_readable_u64(out, v); |
| else |
| bch2_prt_printf(out, "%llu", v); |
| } |
| |
| /** |
| * bch2_prt_units_s64() - Print out a s64 according to printbuf unit options |
| * @out: output printbuf |
| * @v: integer to print |
| * |
| * Units are either raw (default), or human reabable units (controlled via |
| * @buf->human_readable_units) |
| */ |
| void bch2_prt_units_s64(struct printbuf *out, s64 v) |
| { |
| if (v < 0) |
| prt_char(out, '-'); |
| bch2_prt_units_u64(out, abs(v)); |
| } |
| |
| void bch2_prt_string_option(struct printbuf *out, |
| const char * const list[], |
| size_t selected) |
| { |
| size_t i; |
| |
| for (i = 0; list[i]; i++) |
| bch2_prt_printf(out, i == selected ? "[%s] " : "%s ", list[i]); |
| } |
| |
| void bch2_prt_bitflags(struct printbuf *out, |
| const char * const list[], u64 flags) |
| { |
| unsigned bit, nr = 0; |
| bool first = true; |
| |
| while (list[nr]) |
| nr++; |
| |
| while (flags && (bit = __ffs64(flags)) < nr) { |
| if (!first) |
| bch2_prt_printf(out, ","); |
| first = false; |
| bch2_prt_printf(out, "%s", list[bit]); |
| flags ^= BIT_ULL(bit); |
| } |
| } |
| |
| void bch2_prt_bitflags_vector(struct printbuf *out, |
| const char * const list[], |
| unsigned long *v, unsigned nr) |
| { |
| bool first = true; |
| unsigned i; |
| |
| for (i = 0; i < nr; i++) |
| if (!list[i]) { |
| nr = i - 1; |
| break; |
| } |
| |
| for_each_set_bit(i, v, nr) { |
| if (!first) |
| bch2_prt_printf(out, ","); |
| first = false; |
| bch2_prt_printf(out, "%s", list[i]); |
| } |
| } |