Index: kernel/generic/src/lib/string.c =================================================================== --- kernel/generic/src/lib/string.c (revision 82bb9c121efbe640882ffd5dbdc9101eb995d0fa) +++ kernel/generic/src/lib/string.c (revision b888d5f6cda37a2986ddbe2619c8524b029f7077) @@ -38,25 +38,66 @@ * strings, called just strings are encoded in UTF-8. Wide strings (encoded * in UTF-32) are supported to a limited degree. A single character is - * represented as wchar_t. - * - * Strings have the following metrics: - * - * Metric Abbrev. Meaning - * ------ ------ ------- - * size n Number of bytes the string is encoded into, excluding - * the null terminator. - * length l The number of characters in the string, excluding - * the null terminator. - * width w The number of character cells the string takes up on a - * monospace display. - * - * Naming scheme: - * - * chr_xxx operate on characters - * str_xxx operate on strings - * wstr_xxx operate on wide strings - * - * [w]str_[n|l|w]xxx operate on a prefix limited by size, length - * or width. + * represented as wchar_t.@n + * + * Overview of the terminology:@n + * + * Term Meaning + * -------------------- ---------------------------------------------------- + * byte 8 bits stored in uint8_t (unsigned 8 bit integer) + * + * character UTF-32 encoded Unicode character, stored in wchar_t + * (signed 32 bit integer), code points 0 .. 1114111 + * are valid + * + * ASCII character 7 bit encoded ASCII character, stored in char + * (usually signed 8 bit integer), code points 0 .. 127 + * are valid + * + * string UTF-8 encoded NULL-terminated Unicode string, char * + * + * wide string UTF-32 encoded NULL-terminated Unicode string, + * wchar_t * + * + * [wide] string size number of BYTES in a [wide] string (excluding + * the NULL-terminator), size_t + * + * [wide] string length number of CHARACTERS in a [wide] string (excluding + * the NULL-terminator), count_t + * + * [wide] string width number of display cells on a monospace display taken + * by a [wide] string, count_t + * + * + * Overview of string metrics:@n + * + * Metric Abbrev. Type Meaning + * ------ ------ ------ ------------------------------------------------- + * size n size_t number of BYTES in a string (excluding the + * NULL-terminator) + * + * length l count_t number of CHARACTERS in a string (excluding the + * null terminator) + * + * width w count_t number of display cells on a monospace display + * taken by a string + * + * + * Function naming prefixes:@n + * + * chr_ operate on characters + * ascii_ operate on ASCII characters + * str_ operate on strings + * wstr_ operate on wide strings + * + * [w]str_[n|l|w] operate on a prefix limited by size, length + * or width + * + * + * A specific character inside a [wide] string can be referred to by:@n + * + * pointer (char *, wchar_t *) + * byte offset (size_t) + * character index (count_t) + * */ @@ -67,49 +108,48 @@ #include #include -#include +#include char invalch = '?'; -/** Byte mask consisting of lowest @n bits (out of eight). */ -#define LO_MASK_8(n) ((uint8_t)((1 << (n)) - 1)) - -/** Byte mask consisting of lowest @n bits (out of 32). */ -#define LO_MASK_32(n) ((uint32_t)((1 << (n)) - 1)) - -/** Byte mask consisting of highest @n bits (out of eight). */ -#define HI_MASK_8(n) (~LO_MASK_8(8 - (n))) - -/** Number of data bits in a UTF-8 continuation byte. */ -#define CONT_BITS 6 - -/** Decode a single character from a substring. - * - * Decode a single character from a substring of size @a sz. Decoding starts +/** Byte mask consisting of lowest @n bits (out of 8) */ +#define LO_MASK_8(n) ((uint8_t) ((1 << (n)) - 1)) + +/** Byte mask consisting of lowest @n bits (out of 32) */ +#define LO_MASK_32(n) ((uint32_t) ((1 << (n)) - 1)) + +/** Byte mask consisting of highest @n bits (out of 8) */ +#define HI_MASK_8(n) (~LO_MASK_8(8 - (n))) + +/** Number of data bits in a UTF-8 continuation byte */ +#define CONT_BITS 6 + +/** Decode a single character from a string. + * + * Decode a single character from a string of size @a size. Decoding starts * at @a offset and this offset is moved to the beginning of the next * character. In case of decoding error, offset generally advances at least - * by one. However, offset is never moved beyond (str + sz). - * - * @param str String (not necessarily NULL-terminated). - * @param index Index (counted in plain characters) where to start - * the decoding. - * @param limit Size of the substring. - * - * @return Value of decoded character or '?' on decoding error. - */ -wchar_t chr_decode(const char *str, size_t *offset, size_t sz) -{ - uint8_t b0, b; /* Bytes read from str. */ - wchar_t ch; - - int b0_bits; /* Data bits in first byte. */ - int cbytes; /* Number of continuation bytes. */ - - if (*offset + 1 > sz) - return invalch; - - b0 = (uint8_t) str[(*offset)++]; - - /* Determine code length. */ - + * by one. However, offset is never moved beyond size. + * + * @param str String (not necessarily NULL-terminated). + * @param offset Byte offset in string where to start decoding. + * @param size Size of the string (in bytes). + * + * @return Value of decoded character, invalch on decoding error or + * NULL if attempt to decode beyond @a size. + * + */ +wchar_t str_decode(const char *str, size_t *offset, size_t size) +{ + if (*offset + 1 > size) + return 0; + + /* First byte read from string */ + uint8_t b0 = (uint8_t) str[(*offset)++]; + + /* Determine code length */ + + unsigned int b0_bits; /* Data bits in first byte */ + unsigned int cbytes; /* Number of continuation bytes */ + if ((b0 & 0x80) == 0) { /* 0xxxxxxx (Plain ASCII) */ @@ -129,28 +169,26 @@ cbytes = 3; } else { - /* 10xxxxxx -- unexpected continuation byte. */ + /* 10xxxxxx -- unexpected continuation byte */ return invalch; } - - if (*offset + cbytes > sz) { + + if (*offset + cbytes > size) return invalch; - } - - ch = b0 & LO_MASK_8(b0_bits); - - /* Decode continuation bytes. */ + + wchar_t ch = b0 & LO_MASK_8(b0_bits); + + /* Decode continuation bytes */ while (cbytes > 0) { - b = (uint8_t) str[(*offset)++]; - - /* Must be 10xxxxxx. */ - if ((b & 0xc0) != 0x80) { + uint8_t b = (uint8_t) str[(*offset)++]; + + /* Must be 10xxxxxx */ + if ((b & 0xc0) != 0x80) return invalch; - } - - /* Shift data bits to ch. */ + + /* Shift data bits to ch */ ch = (ch << CONT_BITS) | (wchar_t) (b & LO_MASK_8(CONT_BITS)); - --cbytes; - } - + cbytes--; + } + return ch; } @@ -162,8 +200,8 @@ * is moved to the position where the next character can be written to. * - * @param ch Input character. - * @param str Output buffer. - * @param offset Offset (in bytes) where to start writing. - * @param sz Size of the output buffer. + * @param ch Input character. + * @param str Output buffer. + * @param offset Byte offset where to start writing. + * @param size Size of the output buffer (in bytes). * * @return EOK if the character was encoded successfully, EOVERFLOW if there @@ -171,22 +209,21 @@ * code was invalid. */ -int chr_encode(wchar_t ch, char *str, size_t *offset, size_t sz) -{ - uint32_t cc; /* Unsigned version of ch. */ - - int cbytes; /* Number of continuation bytes. */ - int b0_bits; /* Number of data bits in first byte. */ - int i; - - if (*offset >= sz) +int chr_encode(const wchar_t ch, char *str, size_t *offset, size_t size) +{ + if (*offset >= size) return EOVERFLOW; - - if (ch < 0) + + if (!chr_check(ch)) return EINVAL; - - /* Bit operations should only be done on unsigned numbers. */ - cc = (uint32_t) ch; - - /* Determine how many continuation bytes are needed. */ + + /* Unsigned version of ch (bit operations should only be done + on unsigned types). */ + uint32_t cc = (uint32_t) ch; + + /* Determine how many continuation bytes are needed */ + + unsigned int b0_bits; /* Data bits in first byte */ + unsigned int cbytes; /* Number of continuation bytes */ + if ((cc & ~LO_MASK_32(7)) == 0) { b0_bits = 7; @@ -202,124 +239,183 @@ cbytes = 3; } else { - /* Codes longer than 21 bits are not supported. */ + /* Codes longer than 21 bits are not supported */ return EINVAL; } - - /* Check for available space in buffer. */ - if (*offset + cbytes >= sz) + + /* Check for available space in buffer */ + if (*offset + cbytes >= size) return EOVERFLOW; - - /* Encode continuation bytes. */ - for (i = cbytes; i > 0; --i) { + + /* Encode continuation bytes */ + unsigned int i; + for (i = cbytes; i > 0; i--) { str[*offset + i] = 0x80 | (cc & LO_MASK_32(CONT_BITS)); cc = cc >> CONT_BITS; } - - /* Encode first byte. */ + + /* Encode first byte */ str[*offset] = (cc & LO_MASK_32(b0_bits)) | HI_MASK_8(8 - b0_bits - 1); - - /* Advance offset. */ - *offset += (1 + cbytes); + + /* Advance offset */ + *offset += cbytes + 1; return EOK; } -/** Get display width of character. - * - * @param ch The character. - * @return Character width in display cells. - */ -count_t chr_width(wchar_t ch) -{ - return 1; -} - -/** Get size of string, with length limit. +/** Get size of string. + * + * Get the number of bytes which are used by the string @a str (excluding the + * NULL-terminator). + * + * @param str String to consider. + * + * @return Number of bytes used by the string + * + */ +size_t str_size(const char *str) +{ + size_t size = 0; + + while (*str++ != 0) + size++; + + return size; +} + +/** Get size of wide string. + * + * Get the number of bytes which are used by the wide string @a str (excluding the + * NULL-terminator). + * + * @param str Wide string to consider. + * + * @return Number of bytes used by the wide string + * + */ +size_t wstr_size(const wchar_t *str) +{ + return (wstr_length(str) * sizeof(wchar_t)); +} + +/** Get size of string with length limit. * * Get the number of bytes which are used by up to @a max_len first * characters in the string @a str. If @a max_len is greater than - * the length of @a str, the entire string is measured. - * - * @param str String to consider. - * @param count Maximum number of characters to measure. - * - * @return Number of bytes used by the characters. + * the length of @a str, the entire string is measured (excluding the + * NULL-terminator). + * + * @param str String to consider. + * @param max_len Maximum number of characters to measure. + * + * @return Number of bytes used by the characters. + * */ size_t str_lsize(const char *str, count_t max_len) { count_t len = 0; - size_t cur = 0; - size_t prev; - wchar_t ch; - - while (true) { - prev = cur; - if (len >= max_len) + size_t offset = 0; + + while (len < max_len) { + if (str_decode(str, &offset, STR_NO_LIMIT) == 0) break; - ch = chr_decode(str, &cur, UTF8_NO_LIMIT); - if (ch == '\0') break; - + len++; } - - return prev; -} - -/** Get size of string, with width limit. - * - * Get the number of bytes which are used by the longest prefix of @a str - * that can fit into @a max_width display cells. - * - * @param str String to consider. - * @param count Maximum number of display cells. - * - * @return Number of bytes used by the characters that fit. - */ -size_t str_wsize(const char *str, count_t max_width) -{ - count_t width = 0; - size_t cur = 0; - size_t prev; - wchar_t ch; - - while (true) { - prev = cur; - if (width >= max_width) - break; - ch = chr_decode(str, &cur, UTF8_NO_LIMIT); - if (ch == '\0') break; - - width += chr_width(ch); - } - - return prev; -} - - -/** Get length of wide string, with width limit. - * - * Get the number of characters in a wide string that can fit into @a max_width - * display cells. - * - * @param wstr Wide string to consider. - * @param count Maximum number of display cells. - * - * @return Number of bytes used by the characters that fit. - */ -count_t wstr_wlength(const wchar_t *wstr, count_t max_width) -{ - count_t width = 0; - index_t cur = 0; - - while (true) { - if (width >= max_width) - break; - if (wstr[cur] == '\0') break; - - width += chr_width(wstr[cur]); - ++cur; - } - - return (count_t) cur; + + return offset; +} + +/** Get size of wide string with length limit. + * + * Get the number of bytes which are used by up to @a max_len first + * wide characters in the wide string @a str. If @a max_len is greater than + * the length of @a str, the entire wide string is measured (excluding the + * NULL-terminator). + * + * @param str Wide string to consider. + * @param max_len Maximum number of wide characters to measure. + * + * @return Number of bytes used by the wide characters. + * + */ +size_t wstr_lsize(const wchar_t *str, count_t max_len) +{ + return (wstr_nlength(str, max_len * sizeof(wchar_t)) * sizeof(wchar_t)); +} + +/** Get number of characters in a string. + * + * @param str NULL-terminated string. + * + * @return Number of characters in string. + * + */ +count_t str_length(const char *str) +{ + count_t len = 0; + size_t offset = 0; + + while (str_decode(str, &offset, STR_NO_LIMIT) != 0) + len++; + + return len; +} + +/** Get number of characters in a wide string. + * + * @param str NULL-terminated wide string. + * + * @return Number of characters in @a str. + * + */ +count_t wstr_length(const wchar_t *wstr) +{ + count_t len = 0; + + while (*wstr++ != 0) + len++; + + return len; +} + +/** Get number of characters in a string with size limit. + * + * @param str NULL-terminated string. + * @param size Maximum number of bytes to consider. + * + * @return Number of characters in string. + * + */ +count_t str_nlength(const char *str, size_t size) +{ + count_t len = 0; + size_t offset = 0; + + while (str_decode(str, &offset, size) != 0) + len++; + + return len; +} + +/** Get number of characters in a string with size limit. + * + * @param str NULL-terminated string. + * @param size Maximum number of bytes to consider. + * + * @return Number of characters in string. + * + */ +count_t wstr_nlength(const wchar_t *str, size_t size) +{ + count_t len = 0; + count_t limit = ALIGN_DOWN(size, sizeof(wchar_t)); + count_t offset = 0; + + while ((offset < limit) && (*str++ != 0)) { + len++; + offset += sizeof(wchar_t); + } + + return len; } @@ -337,9 +433,10 @@ } -/** Check whether character is Unicode. - * - * @return True if character is valid Unicode code point. - */ -bool unicode_check(const wchar_t ch) +/** Check whether character is valid + * + * @return True if character is a valid Unicode code point. + * + */ +bool chr_check(const wchar_t ch) { if ((ch >= 0) && (ch <= 1114111)) @@ -349,77 +446,42 @@ } -/** Return number of bytes the string occupies. - * - * @param str A string. - * @return Number of bytes in @a str excluding the null terminator. - */ -size_t str_size(const char *str) -{ - size_t size; - - size = 0; - while (*str++ != '\0') - ++size; - - return size; -} - -/** Return number of characters in a string. - * - * @param str NULL-terminated string. - * @return Number of characters in string. - */ -count_t str_length(const char *str) -{ - count_t len = 0; - size_t offset = 0; - - while (chr_decode(str, &offset, UTF8_NO_LIMIT) != 0) { - len++; - } - - return len; -} - -/** Return number of characters in a wide string. - * - * @param str NULL-terminated wide string. - * @return Number of characters in @a str. - */ -count_t wstr_length(const wchar_t *wstr) -{ - count_t len; - - len = 0; - while (*wstr++ != '\0') - ++len; - - return len; -} - -/** Compare two NULL terminated strings - * - * Do a char-by-char comparison of two NULL terminated strings. +/** Compare two NULL terminated strings. + * + * Do a char-by-char comparison of two NULL-terminated strings. * The strings are considered equal iff they consist of the same * characters on the minimum of their lengths. * - * @param src First string to compare. - * @param dst Second string to compare. - * - * @return 0 if the strings are equal, -1 if first is smaller, 1 if second smaller. - * - */ -int strcmp(const char *src, const char *dst) -{ - for (; *src && *dst; src++, dst++) { - if (*src < *dst) + * @param s1 First string to compare. + * @param s2 Second string to compare. + * + * @return 0 if the strings are equal, -1 if first is smaller, + * 1 if second smaller. + * + */ +int str_cmp(const char *s1, const char *s2) +{ + wchar_t c1; + wchar_t c2; + + size_t off1 = 0; + size_t off2 = 0; + + while ((c1 = str_decode(s1, &off1, STR_NO_LIMIT) != 0) + && (c2 = str_decode(s2, &off2, STR_NO_LIMIT) != 0)) { + + if (off1 != off2) + break; + + if (c1 < c2) return -1; - if (*src > *dst) + + if (c1 > c2) return 1; } - if (*src == *dst) + + if ((off1 == off2) && (c1 == c2)) return 0; - if (!*src) + if ((c1 == 0) || (off1 < off2)) return -1; @@ -427,34 +489,48 @@ } - -/** Compare two NULL terminated strings - * - * Do a char-by-char comparison of two NULL terminated strings. +/** Compare two NULL terminated strings with length limit. + * + * Do a char-by-char comparison of two NULL-terminated strings. * The strings are considered equal iff they consist of the same - * characters on the minimum of their lengths and specified maximal - * length. - * - * @param src First string to compare. - * @param dst Second string to compare. - * @param len Maximal length for comparison. - * - * @return 0 if the strings are equal, -1 if first is smaller, 1 if second smaller. - */ -int strncmp(const char *src, const char *dst, size_t len) -{ - unsigned int i; - - for (i = 0; (*src) && (*dst) && (i < len); src++, dst++, i++) { - if (*src < *dst) + * characters on the minimum of their lengths and the length limit. + * + * @param s1 First string to compare. + * @param s2 Second string to compare. + * @param max_len Maximum number of characters to consider. + * + * @return 0 if the strings are equal, -1 if first is smaller, + * 1 if second smaller. + * + */ +int str_lcmp(const char *s1, const char *s2, count_t max_len) +{ + wchar_t c1 = 0; + wchar_t c2 = 0; + + size_t off1 = 0; + size_t off2 = 0; + + count_t len = 0; + + while ((len < max_len) + && ((c1 = str_decode(s1, &off1, STR_NO_LIMIT)) != 0) + && ((c2 = str_decode(s2, &off2, STR_NO_LIMIT)) != 0)) { + + if (off1 != off2) + break; + + if (c1 < c2) return -1; - if (*src > *dst) + if (c1 > c2) return 1; - } - - if (i == len || *src == *dst) + + len++; + } + + if ((off1 == off2) && (len == max_len) && (c1 == c2)) return 0; - if (!*src) + if ((c1 == 0) || (off1 < off2)) return -1; @@ -462,41 +538,88 @@ } - - -/** Copy NULL terminated string. - * - * Copy at most 'len' characters from string 'src' to 'dest'. - * If 'src' is shorter than 'len', '\0' is inserted behind the - * last copied character. - * - * @param src Source string. - * @param dest Destination buffer. - * @param len Size of destination buffer. - */ -void strncpy(char *dest, const char *src, size_t len) -{ - unsigned int i; - - for (i = 0; i < len; i++) { - if (!(dest[i] = src[i])) - return; - } - - dest[i - 1] = '\0'; +/** Copy NULL-terminated string. + * + * Copy source string @a src to destination buffer @a dst. + * No more than @a size bytes are written. NULL-terminator is always + * written after the last succesfully copied character (i.e. if the + * destination buffer is has at least 1 byte, it will be always + * NULL-terminated). + * + * @param src Source string. + * @param dst Destination buffer. + * @param count Size of the destination buffer. + * + */ +void str_ncpy(char *dst, const char *src, size_t size) +{ + /* No space for the NULL-terminator in the buffer */ + if (size == 0) + return; + + wchar_t ch; + size_t str_off = 0; + size_t dst_off = 0; + + while ((ch = str_decode(src, &str_off, STR_NO_LIMIT) != 0)) { + if (chr_encode(ch, dst, &dst_off, size) != EOK) + break; + } + + if (dst_off >= size) + dst[size - 1] = 0; + else + dst[dst_off] = 0; +} + +/** Copy NULL-terminated wide string to string + * + * Copy source wide string @a src to destination buffer @a dst. + * No more than @a size bytes are written. NULL-terminator is always + * written after the last succesfully copied character (i.e. if the + * destination buffer is has at least 1 byte, it will be always + * NULL-terminated). + * + * @param src Source wide string. + * @param dst Destination buffer. + * @param count Size of the destination buffer. + * + */ +void wstr_nstr(char *dst, const wchar_t *src, size_t size) +{ + /* No space for the NULL-terminator in the buffer */ + if (size == 0) + return; + + wchar_t ch; + count_t src_idx = 0; + size_t dst_off = 0; + + while ((ch = src[src_idx++]) != 0) { + if (chr_encode(ch, dst, &dst_off, size) != EOK) + break; + } + + if (dst_off >= size) + dst[size - 1] = 0; + else + dst[dst_off] = 0; } /** Find first occurence of character in string. * - * @param s String to search. - * @param i Character to look for. - * - * @return Pointer to character in @a s or NULL if not found. - */ -extern char *strchr(const char *s, int i) -{ - while (*s != '\0') { - if (*s == i) - return (char *) s; - ++s; + * @param str String to search. + * @param ch Character to look for. + * + * @return Pointer to character in @a str or NULL if not found. + * + */ +const char *str_chr(const char *str, wchar_t ch) +{ + wchar_t acc; + size_t off = 0; + + while ((acc = str_decode(str, &off, STR_NO_LIMIT) != 0)) { + if (acc == ch) + return (str + off); } @@ -504,4 +627,60 @@ } +/** Insert a wide character into a wide string. + * + * Insert a wide character into a wide string at position + * @a pos. The characters after the position are shifted. + * + * @param str String to insert to. + * @param ch Character to insert to. + * @param pos Character index where to insert. + @ @param max_pos Characters in the buffer. + * + * @return True if the insertion was sucessful, false if the position + * is out of bounds. + * + */ +bool wstr_linsert(wchar_t *str, wchar_t ch, count_t pos, count_t max_pos) +{ + count_t len = wstr_length(str); + + if ((pos > len) || (pos + 1 > max_pos)) + return false; + + count_t i; + for (i = len; i + 1 > pos; i--) + str[i + 1] = str[i]; + + str[pos] = ch; + + return true; +} + +/** Remove a wide character from a wide string. + * + * Remove a wide character from a wide string at position + * @a pos. The characters after the position are shifted. + * + * @param str String to remove from. + * @param pos Character index to remove. + * + * @return True if the removal was sucessful, false if the position + * is out of bounds. + * + */ +bool wstr_remove(wchar_t *str, count_t pos) +{ + count_t len = wstr_length(str); + + if (pos >= len) + return false; + + count_t i; + for (i = pos + 1; i <= len; i++) + str[i - 1] = str[i]; + + return true; +} + /** @} */