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-rw-r--r--lib/printbuf.c274
1 files changed, 274 insertions, 0 deletions
diff --git a/lib/printbuf.c b/lib/printbuf.c
new file mode 100644
index 000000000000..e0dfa82cdad6
--- /dev/null
+++ b/lib/printbuf.c
@@ -0,0 +1,274 @@
+// SPDX-License-Identifier: LGPL-2.1+
+/* Copyright (C) 2022 Kent Overstreet */
+
+#ifdef __KERNEL__
+#include <linux/export.h>
+#include <linux/kernel.h>
+#else
+#define EXPORT_SYMBOL(x)
+#endif
+
+#include <linux/log2.h>
+#include <linux/printbuf.h>
+#include <linux/string_helpers.h>
+
+static inline size_t printbuf_remaining(struct printbuf *buf)
+{
+ return buf->size - buf->pos;
+}
+
+static inline size_t printbuf_linelen(struct printbuf *buf)
+{
+ return buf->pos - buf->last_newline;
+}
+
+static int printbuf_realloc(struct printbuf *out, unsigned extra)
+{
+ unsigned new_size;
+ char *buf;
+
+ if (out->pos + extra + 1 < out->size)
+ return 0;
+
+ new_size = roundup_pow_of_two(out->size + extra);
+ buf = krealloc(out->buf, new_size, !out->atomic ? GFP_KERNEL : GFP_ATOMIC);
+
+ if (!buf) {
+ out->allocation_failure = true;
+ return -ENOMEM;
+ }
+
+ out->buf = buf;
+ out->size = new_size;
+ return 0;
+}
+
+void pr_buf(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) &&
+ !printbuf_realloc(out, len + 1));
+
+ len = min_t(size_t, len,
+ printbuf_remaining(out) ? printbuf_remaining(out) - 1 : 0);
+ out->pos += len;
+}
+EXPORT_SYMBOL(pr_buf);
+
+void pr_char(struct printbuf *buf, char c)
+{
+ if (!printbuf_realloc(buf, 1)) {
+ buf->buf[buf->pos++] = c;
+ buf->buf[buf->pos] = 0;
+ }
+}
+EXPORT_SYMBOL(pr_char);
+
+void pr_newline(struct printbuf *buf)
+{
+ unsigned i;
+
+ pr_char(buf, '\n');
+
+ buf->last_newline = buf->pos;
+
+ for (i = 0; i < buf->indent; i++)
+ pr_char(buf, ' ');
+
+ buf->last_field = buf->pos;
+ buf->tabstop = 0;
+}
+EXPORT_SYMBOL(pr_newline);
+
+void pr_indent_push(struct printbuf *buf, unsigned spaces)
+{
+ buf->indent += spaces;
+ while (spaces--)
+ pr_char(buf, ' ');
+}
+EXPORT_SYMBOL(pr_indent_push);
+
+void pr_indent_pop(struct printbuf *buf, unsigned spaces)
+{
+ if (buf->last_newline + buf->indent == buf->pos) {
+ buf->pos -= spaces;
+ buf->buf[buf->pos] = 0;
+ }
+ buf->indent -= spaces;
+}
+EXPORT_SYMBOL(pr_indent_pop);
+
+void pr_tab(struct printbuf *buf)
+{
+ BUG_ON(buf->tabstop > ARRAY_SIZE(buf->tabstops));
+
+ while (printbuf_remaining(buf) > 1 &&
+ printbuf_linelen(buf) < buf->tabstops[buf->tabstop])
+ pr_char(buf, ' ');
+
+ buf->last_field = buf->pos;
+ buf->tabstop++;
+}
+EXPORT_SYMBOL(pr_tab);
+
+void pr_tab_rjust(struct printbuf *buf)
+{
+ BUG_ON(buf->tabstop > ARRAY_SIZE(buf->tabstops));
+
+ if (printbuf_linelen(buf) < buf->tabstops[buf->tabstop]) {
+ unsigned move = buf->pos - buf->last_field;
+ unsigned shift = buf->tabstops[buf->tabstop] -
+ printbuf_linelen(buf);
+
+ printbuf_realloc(buf, shift);
+
+ if (buf->last_field + shift + 1 < buf->size) {
+ move = min(move, buf->size - 1 - buf->last_field - shift);
+
+ memmove(buf->buf + buf->last_field + shift,
+ buf->buf + buf->last_field,
+ move);
+ memset(buf->buf + buf->last_field, ' ', shift);
+ buf->pos += shift;
+ buf->buf[buf->pos] = 0;
+ }
+ }
+
+ buf->last_field = buf->pos;
+ buf->tabstop++;
+}
+EXPORT_SYMBOL(pr_tab_rjust);
+
+void pr_human_readable_u64(struct printbuf *buf, u64 v)
+{
+ printbuf_realloc(buf, 10);
+ string_get_size(v, 1, buf->human_readable_units, buf->buf + buf->pos,
+ printbuf_remaining(buf));
+ buf->pos += strlen(buf->buf + buf->pos);
+}
+EXPORT_SYMBOL(pr_human_readable_u64);
+
+void pr_human_readable_s64(struct printbuf *buf, s64 v)
+{
+ if (v < 0)
+ pr_char(buf, '-');
+ pr_human_readable_u64(buf, abs(v));
+}
+EXPORT_SYMBOL(pr_human_readable_s64);
+
+void pr_units(struct printbuf *out, s64 raw, s64 bytes)
+{
+ switch (out->units) {
+ case PRINTBUF_UNITS_RAW:
+ pr_buf(out, "%llu", raw);
+ break;
+ case PRINTBUF_UNITS_BYTES:
+ pr_buf(out, "%llu", bytes);
+ break;
+ case PRINTBUF_UNITS_HUMAN_READABLE:
+ pr_human_readable_s64(out, bytes);
+ break;
+ }
+}
+EXPORT_SYMBOL(pr_units);
+
+void pr_sectors(struct printbuf *out, u64 v)
+{
+ pr_units(out, v, v << 9);
+}
+EXPORT_SYMBOL(pr_sectors);
+
+#ifdef __KERNEL__
+
+void pr_time(struct printbuf *out, u64 time)
+{
+ pr_buf(out, "%llu", time);
+}
+EXPORT_SYMBOL(pr_time);
+
+void pr_uuid(struct printbuf *out, u8 *uuid)
+{
+ pr_buf(out, "%pUb", uuid);
+}
+EXPORT_SYMBOL(pr_uuid);
+
+#else
+
+#include <time.h>
+#include <uuid.h>
+
+void pr_time(struct printbuf *out, u64 _time)
+{
+ char time_str[64];
+ time_t time = _time;
+ struct tm *tm = localtime(&time);
+ size_t err = strftime(time_str, sizeof(time_str), "%c", tm);
+
+ if (!err)
+ pr_buf(out, "(formatting error)");
+ else
+ pr_buf(out, "%s", time_str);
+}
+
+void pr_uuid(struct printbuf *out, u8 *uuid)
+{
+ char uuid_str[40];
+
+ uuid_unparse_lower(uuid, uuid_str);
+ pr_buf(out, uuid_str);
+}
+
+#endif
+
+void pr_string_option(struct printbuf *out,
+ const char * const list[],
+ size_t selected)
+{
+ size_t i;
+
+ for (i = 0; list[i]; i++)
+ pr_buf(out, i == selected ? "[%s] " : "%s ", list[i]);
+}
+EXPORT_SYMBOL(pr_string_option);
+
+void pr_bitflags(struct printbuf *out,
+ const char * const list[], u64 flags)
+{
+ unsigned bit, nr = 0;
+ bool first = true;
+
+ while (list[nr])
+ nr++;
+
+ while (flags && (bit = __ffs(flags)) < nr) {
+ if (!first)
+ pr_buf(out, ",");
+ first = false;
+ pr_buf(out, "%s", list[bit]);
+ flags ^= 1 << bit;
+ }
+}
+EXPORT_SYMBOL(pr_bitflags);
+
+/**
+ * printbuf_str - returns printbuf's buf as a C string, guaranteed to be null
+ * terminated
+ */
+const char *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
+ : "";
+}
+EXPORT_SYMBOL(printbuf_str);