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-rw-r--r--misc/bstr.c469
1 files changed, 469 insertions, 0 deletions
diff --git a/misc/bstr.c b/misc/bstr.c
new file mode 100644
index 0000000..4f1e862
--- /dev/null
+++ b/misc/bstr.c
@@ -0,0 +1,469 @@
+/*
+ * This file is part of mpv.
+ *
+ * mpv is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * mpv is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with mpv. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <string.h>
+#include <strings.h>
+#include <assert.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "mpv_talloc.h"
+
+#include "common/common.h"
+#include "misc/ctype.h"
+#include "bstr.h"
+
+int bstrcmp(struct bstr str1, struct bstr str2)
+{
+ int ret = 0;
+ if (str1.len && str2.len)
+ ret = memcmp(str1.start, str2.start, MPMIN(str1.len, str2.len));
+
+ if (!ret) {
+ if (str1.len == str2.len)
+ return 0;
+ else if (str1.len > str2.len)
+ return 1;
+ else
+ return -1;
+ }
+ return ret;
+}
+
+int bstrcasecmp(struct bstr str1, struct bstr str2)
+{
+ int ret = 0;
+ if (str1.len && str2.len)
+ ret = strncasecmp(str1.start, str2.start, MPMIN(str1.len, str2.len));
+
+ if (!ret) {
+ if (str1.len == str2.len)
+ return 0;
+ else if (str1.len > str2.len)
+ return 1;
+ else
+ return -1;
+ }
+ return ret;
+}
+
+int bstrchr(struct bstr str, int c)
+{
+ for (int i = 0; i < str.len; i++)
+ if (str.start[i] == c)
+ return i;
+ return -1;
+}
+
+int bstrrchr(struct bstr str, int c)
+{
+ for (int i = str.len - 1; i >= 0; i--)
+ if (str.start[i] == c)
+ return i;
+ return -1;
+}
+
+int bstrcspn(struct bstr str, const char *reject)
+{
+ int i;
+ for (i = 0; i < str.len; i++)
+ if (strchr(reject, str.start[i]))
+ break;
+ return i;
+}
+
+int bstrspn(struct bstr str, const char *accept)
+{
+ int i;
+ for (i = 0; i < str.len; i++)
+ if (!strchr(accept, str.start[i]))
+ break;
+ return i;
+}
+
+int bstr_find(struct bstr haystack, struct bstr needle)
+{
+ for (int i = 0; i < haystack.len; i++)
+ if (bstr_startswith(bstr_splice(haystack, i, haystack.len), needle))
+ return i;
+ return -1;
+}
+
+struct bstr bstr_lstrip(struct bstr str)
+{
+ while (str.len && mp_isspace(*str.start)) {
+ str.start++;
+ str.len--;
+ }
+ return str;
+}
+
+struct bstr bstr_strip(struct bstr str)
+{
+ str = bstr_lstrip(str);
+ while (str.len && mp_isspace(str.start[str.len - 1]))
+ str.len--;
+ return str;
+}
+
+struct bstr bstr_split(struct bstr str, const char *sep, struct bstr *rest)
+{
+ int start;
+ for (start = 0; start < str.len; start++)
+ if (!strchr(sep, str.start[start]))
+ break;
+ str = bstr_cut(str, start);
+ int end = bstrcspn(str, sep);
+ if (rest) {
+ *rest = bstr_cut(str, end);
+ }
+ return bstr_splice(str, 0, end);
+}
+
+// Unlike with bstr_split(), tok is a string, and not a set of char.
+// If tok is in str, return true, and: concat(out_left, tok, out_right) == str
+// Otherwise, return false, and set out_left==str, out_right==""
+bool bstr_split_tok(bstr str, const char *tok, bstr *out_left, bstr *out_right)
+{
+ bstr bsep = bstr0(tok);
+ int pos = bstr_find(str, bsep);
+ if (pos < 0)
+ pos = str.len;
+ *out_left = bstr_splice(str, 0, pos);
+ *out_right = bstr_cut(str, pos + bsep.len);
+ return pos != str.len;
+}
+
+struct bstr bstr_splice(struct bstr str, int start, int end)
+{
+ if (start < 0)
+ start += str.len;
+ if (end < 0)
+ end += str.len;
+ end = MPMIN(end, str.len);
+ start = MPMAX(start, 0);
+ end = MPMAX(end, start);
+ str.start += start;
+ str.len = end - start;
+ return str;
+}
+
+long long bstrtoll(struct bstr str, struct bstr *rest, int base)
+{
+ str = bstr_lstrip(str);
+ char buf[51];
+ int len = MPMIN(str.len, 50);
+ memcpy(buf, str.start, len);
+ buf[len] = 0;
+ char *endptr;
+ long long r = strtoll(buf, &endptr, base);
+ if (rest)
+ *rest = bstr_cut(str, endptr - buf);
+ return r;
+}
+
+double bstrtod(struct bstr str, struct bstr *rest)
+{
+ str = bstr_lstrip(str);
+ char buf[101];
+ int len = MPMIN(str.len, 100);
+ memcpy(buf, str.start, len);
+ buf[len] = 0;
+ char *endptr;
+ double r = strtod(buf, &endptr);
+ if (rest)
+ *rest = bstr_cut(str, endptr - buf);
+ return r;
+}
+
+struct bstr bstr_splitchar(struct bstr str, struct bstr *rest, const char c)
+{
+ int pos = bstrchr(str, c);
+ if (pos < 0)
+ pos = str.len;
+ if (rest)
+ *rest = bstr_cut(str, pos + 1);
+ return bstr_splice(str, 0, pos + 1);
+}
+
+struct bstr bstr_strip_linebreaks(struct bstr str)
+{
+ if (bstr_endswith0(str, "\r\n")) {
+ str = bstr_splice(str, 0, str.len - 2);
+ } else if (bstr_endswith0(str, "\n")) {
+ str = bstr_splice(str, 0, str.len - 1);
+ }
+ return str;
+}
+
+bool bstr_eatstart(struct bstr *s, struct bstr prefix)
+{
+ if (!bstr_startswith(*s, prefix))
+ return false;
+ *s = bstr_cut(*s, prefix.len);
+ return true;
+}
+
+bool bstr_eatend(struct bstr *s, struct bstr prefix)
+{
+ if (!bstr_endswith(*s, prefix))
+ return false;
+ s->len -= prefix.len;
+ return true;
+}
+
+void bstr_lower(struct bstr str)
+{
+ for (int i = 0; i < str.len; i++)
+ str.start[i] = mp_tolower(str.start[i]);
+}
+
+int bstr_sscanf(struct bstr str, const char *format, ...)
+{
+ char *ptr = bstrdup0(NULL, str);
+ va_list va;
+ va_start(va, format);
+ int ret = vsscanf(ptr, format, va);
+ va_end(va);
+ talloc_free(ptr);
+ return ret;
+}
+
+int bstr_parse_utf8_code_length(unsigned char b)
+{
+ if (b < 128)
+ return 1;
+ int bytes = 7 - mp_log2(b ^ 255);
+ return (bytes >= 2 && bytes <= 4) ? bytes : -1;
+}
+
+int bstr_decode_utf8(struct bstr s, struct bstr *out_next)
+{
+ if (s.len == 0)
+ return -1;
+ unsigned int codepoint = s.start[0];
+ s.start++; s.len--;
+ if (codepoint >= 128) {
+ int bytes = bstr_parse_utf8_code_length(codepoint);
+ if (bytes < 1 || s.len < bytes - 1)
+ return -1;
+ codepoint &= 127 >> bytes;
+ for (int n = 1; n < bytes; n++) {
+ int tmp = (unsigned char)s.start[0];
+ if ((tmp & 0xC0) != 0x80)
+ return -1;
+ codepoint = (codepoint << 6) | (tmp & ~0xC0);
+ s.start++; s.len--;
+ }
+ if (codepoint > 0x10FFFF || (codepoint >= 0xD800 && codepoint <= 0xDFFF))
+ return -1;
+ // Overlong sequences - check taken from libavcodec.
+ // (The only reason we even bother with this is to make libavcodec's
+ // retarded subtitle utf-8 check happy.)
+ unsigned int min = bytes == 2 ? 0x80 : 1 << (5 * bytes - 4);
+ if (codepoint < min)
+ return -1;
+ }
+ if (out_next)
+ *out_next = s;
+ return codepoint;
+}
+
+struct bstr bstr_split_utf8(struct bstr str, struct bstr *out_next)
+{
+ bstr rest;
+ int code = bstr_decode_utf8(str, &rest);
+ if (code < 0)
+ return (bstr){0};
+ if (out_next)
+ *out_next = rest;
+ return bstr_splice(str, 0, str.len - rest.len);
+}
+
+int bstr_validate_utf8(struct bstr s)
+{
+ while (s.len) {
+ if (bstr_decode_utf8(s, &s) < 0) {
+ // Try to guess whether the sequence was just cut-off.
+ unsigned int codepoint = (unsigned char)s.start[0];
+ int bytes = bstr_parse_utf8_code_length(codepoint);
+ if (bytes > 1 && s.len < 6) {
+ // Manually check validity of left bytes
+ for (int n = 1; n < bytes; n++) {
+ if (n >= s.len) {
+ // Everything valid until now - just cut off.
+ return -(bytes - s.len);
+ }
+ int tmp = (unsigned char)s.start[n];
+ if ((tmp & 0xC0) != 0x80)
+ break;
+ }
+ }
+ return -8;
+ }
+ }
+ return 0;
+}
+
+struct bstr bstr_sanitize_utf8_latin1(void *talloc_ctx, struct bstr s)
+{
+ bstr new = {0};
+ bstr left = s;
+ unsigned char *first_ok = s.start;
+ while (left.len) {
+ int r = bstr_decode_utf8(left, &left);
+ if (r < 0) {
+ bstr_xappend(talloc_ctx, &new, (bstr){first_ok, left.start - first_ok});
+ mp_append_utf8_bstr(talloc_ctx, &new, (unsigned char)left.start[0]);
+ left.start += 1;
+ left.len -= 1;
+ first_ok = left.start;
+ }
+ }
+ if (!new.start)
+ return s;
+ if (first_ok != left.start)
+ bstr_xappend(talloc_ctx, &new, (bstr){first_ok, left.start - first_ok});
+ return new;
+}
+
+static void resize_append(void *talloc_ctx, bstr *s, size_t append_min)
+{
+ size_t size = talloc_get_size(s->start);
+ assert(s->len <= size);
+ if (append_min > size - s->len) {
+ if (append_min < size)
+ append_min = size; // preallocate in power of 2s
+ if (size >= SIZE_MAX / 2 || append_min >= SIZE_MAX / 2)
+ abort(); // oom
+ s->start = talloc_realloc_size(talloc_ctx, s->start, size + append_min);
+ }
+}
+
+// Append the string, so that *s = *s + append. s->start is expected to be
+// a talloc allocation (which can be realloced) or NULL.
+// This function will always implicitly append a \0 after the new string for
+// convenience.
+// talloc_ctx will be used as parent context, if s->start is NULL.
+void bstr_xappend(void *talloc_ctx, bstr *s, bstr append)
+{
+ if (!append.len)
+ return;
+ resize_append(talloc_ctx, s, append.len + 1);
+ memcpy(s->start + s->len, append.start, append.len);
+ s->len += append.len;
+ s->start[s->len] = '\0';
+}
+
+void bstr_xappend_asprintf(void *talloc_ctx, bstr *s, const char *fmt, ...)
+{
+ va_list ap;
+ va_start(ap, fmt);
+ bstr_xappend_vasprintf(talloc_ctx, s, fmt, ap);
+ va_end(ap);
+}
+
+// Exactly as bstr_xappend(), but with a formatted string.
+void bstr_xappend_vasprintf(void *talloc_ctx, bstr *s, const char *fmt,
+ va_list ap)
+{
+ int size;
+ va_list copy;
+ va_copy(copy, ap);
+ size_t avail = talloc_get_size(s->start) - s->len;
+ char *dest = s->start ? s->start + s->len : NULL;
+ char c;
+ if (avail < 1)
+ dest = &c;
+ size = vsnprintf(dest, MPMAX(avail, 1), fmt, copy);
+ va_end(copy);
+
+ if (size < 0)
+ abort();
+
+ if (avail < 1 || size + 1 > avail) {
+ resize_append(talloc_ctx, s, size + 1);
+ vsnprintf(s->start + s->len, size + 1, fmt, ap);
+ }
+ s->len += size;
+}
+
+bool bstr_case_startswith(struct bstr s, struct bstr prefix)
+{
+ struct bstr start = bstr_splice(s, 0, prefix.len);
+ return start.len == prefix.len && bstrcasecmp(start, prefix) == 0;
+}
+
+bool bstr_case_endswith(struct bstr s, struct bstr suffix)
+{
+ struct bstr end = bstr_cut(s, -suffix.len);
+ return end.len == suffix.len && bstrcasecmp(end, suffix) == 0;
+}
+
+struct bstr bstr_strip_ext(struct bstr str)
+{
+ int dotpos = bstrrchr(str, '.');
+ if (dotpos < 0)
+ return str;
+ return (struct bstr){str.start, dotpos};
+}
+
+struct bstr bstr_get_ext(struct bstr s)
+{
+ int dotpos = bstrrchr(s, '.');
+ if (dotpos < 0)
+ return (struct bstr){NULL, 0};
+ return bstr_splice(s, dotpos + 1, s.len);
+}
+
+static int h_to_i(unsigned char c)
+{
+ if (c >= '0' && c <= '9')
+ return c - '0';
+ if (c >= 'a' && c <= 'f')
+ return c - 'a' + 10;
+ if (c >= 'A' && c <= 'F')
+ return c - 'A' + 10;
+
+ return -1; // invalid char
+}
+
+bool bstr_decode_hex(void *talloc_ctx, struct bstr hex, struct bstr *out)
+{
+ if (!out)
+ return false;
+
+ char *arr = talloc_array(talloc_ctx, char, hex.len / 2);
+ int len = 0;
+
+ while (hex.len >= 2) {
+ int a = h_to_i(hex.start[0]);
+ int b = h_to_i(hex.start[1]);
+ hex = bstr_splice(hex, 2, hex.len);
+
+ if (a < 0 || b < 0) {
+ talloc_free(arr);
+ return false;
+ }
+
+ arr[len++] = (a << 4) | b;
+ }
+
+ *out = (struct bstr){ .start = arr, .len = len };
+ return true;
+}
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