// 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, unsigned pos)
{
return pos - buf->last_newline;
}
static inline unsigned printbuf_linelen(struct printbuf *buf)
{
return __printbuf_linelen(buf, buf->pos);
}
/*
* 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;
}
int bch2_printbuf_make_room(struct printbuf *out, unsigned extra)
{
/* Reserved space for terminating nul: */
extra += 1;
if (out->pos + extra <= out->size)
return 0;
if (!out->heap_allocated) {
out->overflow = true;
return 0;
}
unsigned new_size = roundup_pow_of_two(out->size + extra);
/* Sanity check... */
if (new_size > PAGE_SIZE << MAX_PAGE_ORDER) {
out->allocation_failure = true;
out->overflow = true;
return -ENOMEM;
}
/*
* Note: output buffer must be freeable with kfree(), it's not required
* that the user use printbuf_exit().
*/
char *buf = krealloc(out->buf, new_size, !out->atomic ? GFP_KERNEL : GFP_NOWAIT);
if (!buf) {
out->allocation_failure = true;
out->overflow = true;
return -ENOMEM;
}
out->buf = buf;
out->size = new_size;
return 0;
}
static void printbuf_advance_pos(struct printbuf *out, unsigned len)
{
out->pos += min(len, printbuf_remaining(out));
}
static void printbuf_insert_spaces(struct printbuf *out, unsigned pos, unsigned nr)
{
unsigned move = out->pos - pos;
bch2_printbuf_make_room(out, nr);
if (pos + nr < out->size)
memmove(out->buf + pos + nr,
out->buf + pos,
min(move, out->size - 1 - pos - nr));
if (pos < out->size)
memset(out->buf + pos, ' ', min(nr, out->size - pos));
printbuf_advance_pos(out, nr);
printbuf_nul_terminate_reserved(out);
}
static void __printbuf_do_indent(struct printbuf *out, unsigned pos)
{
while (true) {
int pad;
unsigned len = out->pos - pos;
char *p = out->buf + pos;
char *n = memscan(p, '\n', len);
if (cur_tabstop(out)) {
n = min(n, (char *) memscan(p, '\r', len));
n = min(n, (char *) memscan(p, '\t', len));
}
pos = n - out->buf;
if (pos == out->pos)
break;
switch (*n) {
case '\n':
pos++;
out->last_newline = pos;
printbuf_insert_spaces(out, pos, out->indent);
pos = min(pos + out->indent, out->pos);
out->last_field = pos;
out->cur_tabstop = 0;
break;
case '\r':
memmove(n, n + 1, out->pos - pos);
--out->pos;
pad = (int) cur_tabstop(out) - (int) __printbuf_linelen(out, pos);
if (pad > 0) {
printbuf_insert_spaces(out, out->last_field, pad);
pos += pad;
}
out->last_field = pos;
out->cur_tabstop++;
break;
case '\t':
pad = (int) cur_tabstop(out) - (int) __printbuf_linelen(out, pos) - 1;
if (pad > 0) {
*n = ' ';
printbuf_insert_spaces(out, pos, pad - 1);
pos += pad;
} else {
memmove(n, n + 1, out->pos - pos);
--out->pos;
}
out->last_field = pos;
out->cur_tabstop++;
break;
}
}
}
static inline void printbuf_do_indent(struct printbuf *out, unsigned pos)
{
if (out->has_indent_or_tabstops && !out->suppress_indent_tabstop_handling)
__printbuf_do_indent(out, pos);
}
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_size(out), fmt, args2);
va_end(args2);
} while (len > printbuf_remaining(out) &&
!bch2_printbuf_make_room(out, len));
unsigned indent_pos = out->pos;
printbuf_advance_pos(out, len);
printbuf_do_indent(out, indent_pos);
}
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_size(out), fmt, args);
va_end(args);
} while (len > printbuf_remaining(out) &&
!bch2_printbuf_make_room(out, len));
unsigned indent_pos = out->pos;
printbuf_advance_pos(out, len);
printbuf_do_indent(out, indent_pos);
}
/**
* 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)
{
bch2_printbuf_make_room(buf, 1 + buf->indent);
__prt_char_reserved(buf, '\n');
buf->last_newline = buf->pos;
__prt_chars_reserved(buf, ' ', buf->indent);
printbuf_nul_terminate_reserved(buf);
buf->last_field = buf->pos;
buf->cur_tabstop = 0;
}
void bch2_printbuf_strip_trailing_newline(struct printbuf *out)
{
for (int p = out->pos - 1; p >= 0; --p) {
if (out->buf[p] == '\n') {
out->pos = p;
break;
}
if (out->buf[p] != ' ')
break;
}
printbuf_nul_terminate_reserved(out);
}
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)
{
int pad = (int) cur_tabstop(buf) - (int) printbuf_linelen(buf);
if (pad > 0)
printbuf_insert_spaces(buf, buf->last_field, pad);
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)
{
unsigned indent_pos = out->pos;
prt_bytes(out, str, count);
printbuf_do_indent(out, indent_pos);
}
/**
* 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);
unsigned len = string_get_size(v, 1, !out->si_units,
out->buf + out->pos,
printbuf_remaining_size(out));
printbuf_advance_pos(out, len);
}
/**
* 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)
{
for (size_t 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]);
}
}
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