/*

 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2016 Nicira, Inc.

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at:

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include <config.h>

#include "openvswitch/dynamic-string.h"

#include <inttypes.h>

#include <stdlib.h>

#include <string.h>

#include <time.h>

#include "timeval.h"

#include "util.h"

/* Initializes 'ds' as an empty string buffer. */

void

ds_init(struct ds *ds)

{

    ds->string = NULL;

    ds->length = 0;

    ds->allocated = 0;

}

/* Sets 'ds''s length to 0, effectively clearing any existing content.  Does

 * not free any memory. */

void

ds_clear(struct ds *ds)

{

    ds->length = 0;

}

/* Reduces 'ds''s length to no more than 'new_length'.  (If its length is

 * already 'new_length' or less, does nothing.)  */

void

ds_truncate(struct ds *ds, size_t new_length)

{

    if (ds->length > new_length) {

        ds->length = new_length;

        ds->string[new_length] = '\0';

    }

}

/* Ensures that at least 'min_length + 1' bytes (including space for a null

 * terminator) are allocated for ds->string, allocating or reallocating memory

 * as necessary. */

void

ds_reserve(struct ds *ds, size_t min_length)

{

    if (min_length > ds->allocated || !ds->string) {

        ds->allocated += MAX(min_length, ds->allocated);

        ds->allocated = MAX(8, ds->allocated);

        ds->string = xrealloc(ds->string, ds->allocated + 1);

    }

}

/* Appends space for 'n' bytes to the end of 'ds->string', increasing

 * 'ds->length' by the same amount, and returns the first appended byte.  The

 * caller should fill in all 'n' bytes starting at the return value. */

char *

ds_put_uninit(struct ds *ds, size_t n)

{

    ds_reserve(ds, ds->length + n);

    ds->length += n;

    ds->string[ds->length] = '\0';

    return &ds->string[ds->length - n];

}

void

ds_put_char__(struct ds *ds, char c)

{

    *ds_put_uninit(ds, 1) = c;

}

/* Appends unicode code point 'uc' to 'ds' in UTF-8 encoding. */

void

ds_put_utf8(struct ds *ds, int uc)

{

    if (uc <= 0x7f) {

        ds_put_char(ds, uc);

    } else if (uc <= 0x7ff) {

        ds_put_char(ds, 0xc0 | (uc >> 6));

        ds_put_char(ds, 0x80 | (uc & 0x3f));

    } else if (uc <= 0xffff) {

        ds_put_char(ds, 0xe0 | (uc >> 12));

        ds_put_char(ds, 0x80 | ((uc >> 6) & 0x3f));

        ds_put_char(ds, 0x80 | (uc & 0x3f));

    } else if (uc <= 0x10ffff) {

        ds_put_char(ds, 0xf0 | (uc >> 18));

        ds_put_char(ds, 0x80 | ((uc >> 12) & 0x3f));

        ds_put_char(ds, 0x80 | ((uc >> 6) & 0x3f));

        ds_put_char(ds, 0x80 | (uc & 0x3f));

    } else {

        /* Invalid code point.  Insert the Unicode general substitute

         * REPLACEMENT CHARACTER. */

        ds_put_utf8(ds, 0xfffd);

    }

}

void

ds_put_char_multiple(struct ds *ds, char c, size_t n)

{

    memset(ds_put_uninit(ds, n), c, n);

}

void

ds_put_buffer(struct ds *ds, const char *s, size_t n)

{

    memcpy(ds_put_uninit(ds, n), s, n);

}

void

ds_put_cstr(struct ds *ds, const char *s)

{

    size_t s_len = strlen(s);

    memcpy(ds_put_uninit(ds, s_len), s, s_len);

}

void

ds_put_and_free_cstr(struct ds *ds, char *s)

{

    ds_put_cstr(ds, s);

    free(s);

}

void

ds_put_format(struct ds *ds, const char *format, ...)

{

    va_list args;

    va_start(args, format);

    ds_put_format_valist(ds, format, args);

    va_end(args);

}

void

ds_put_format_valist(struct ds *ds, const char *format, va_list args_)

{

    va_list args;

    size_t available;

    int needed;

    va_copy(args, args_);

    available = ds->string ? ds->allocated - ds->length + 1 : 0;

    needed = vsnprintf(ds->string

                       ? &ds->string[ds->length]

                       : NULL,

                       available, format, args);

    va_end(args);

    if (needed < available) {

        ds->length += needed;

    } else {

        ds_reserve(ds, ds->length + needed);

        va_copy(args, args_);

        available = ds->allocated - ds->length + 1;

        needed = vsnprintf(&ds->string[ds->length],

                           available, format, args);

        va_end(args);

        ovs_assert(needed < available);

        ds->length += needed;

    }

}

void

ds_put_printable(struct ds *ds, const char *s, size_t n)

{

    ds_reserve(ds, ds->length + n);

    while (n-- > 0) {

        unsigned char c = *s++;

        if (c < 0x20 || c > 0x7e || c == '\\' || c == '"') {

            ds_put_format(ds, "\\%03o", (int) c);

        } else {

            ds_put_char(ds, c);

        }

    }

}

/* Writes the current time with optional millisecond resolution to 'string'

 * based on 'template'.

 * The current time is either localtime or UTC based on 'utc'. */

void

ds_put_strftime_msec(struct ds *ds, const char *template, long long int when,

                     bool utc)

{

    struct tm_msec tm;

    if (utc) {

        gmtime_msec(when, &tm);

    } else {

        localtime_msec(when, &tm);

    }

    ds_reserve(ds, 64);

    for (;;) {

        size_t avail = ds->allocated - ds->length + 1;

        char *dest = &ds->string[ds->length];

        size_t used = strftime_msec(dest, avail, template, &tm);

        if (used) {

            ds->length += used;

            return;

        }

        ds_reserve(ds, ds->length + (avail < 32 ? 64 : 2 * avail));

    }

}

/* Returns a malloc()'d string for time 'when' based on 'template', in local

 * time or UTC based on 'utc'. */

char *

xastrftime_msec(const char *template, long long int when, bool utc)

{

    struct ds s;

    ds_init(&s);

    ds_put_strftime_msec(&s, template, when, utc);

    return s.string;

}

int

ds_get_line(struct ds *ds, FILE *file)

{

    ds_clear(ds);

    for (;;) {

        int c = getc(file);

        if (c == EOF) {

            return ds->length ? 0 : EOF;

        } else if (c == '\n') {

            return 0;

        } else {

            ds_put_char(ds, c);

        }

    }

}

/* Reads a line from 'file' into 'ds', clearing anything initially in 'ds'.

 * Deletes comments introduced by "#" and skips lines that contains only white

 * space (after deleting comments).

 *

 * If 'line_numberp' is nonnull, increments '*line_numberp' by the number of

 * lines read from 'file'.

 *

 * Returns 0 if successful, EOF if no non-blank line was found. */

int

ds_get_preprocessed_line(struct ds *ds, FILE *file, int *line_numberp)

{

    while (!ds_get_line(ds, file)) {

        char *line = ds_cstr(ds);

        char *comment;

        if (line_numberp) {

            ++*line_numberp;

        }

        /* Delete comments. */

        comment = strchr(line, '#');

        if (comment) {

            *comment = '\0';

        }

        /* Return successfully unless the line is all spaces. */

        if (line[strspn(line, " \t\n")] != '\0') {

            return 0;

        }

    }

    return EOF;

}

/* Reads a line from 'file' into 'ds' and does some preprocessing on it:

 *

 *    - If the line begins with #, prints it on stdout and reads the next line.

 *

 *    - Otherwise, if the line contains an # somewhere else, strips it and

 *      everything following it (as a comment).

 *

 *    - If (after comment removal) the line contains only white space, prints

 *      a blank line on stdout and reads the next line.

 *

 *    - Otherwise, returns the line to the caller.

 *

 * This is useful in some of the OVS tests, where we want to check that parsing

 * and then re-formatting some kind of data does not change it, but we also

 * want to be able to put comments in the input.

 *

 * Returns 0 if successful, EOF if no non-blank line was found. */

int

ds_get_test_line(struct ds *ds, FILE *file)

{

    for (;;) {

        char *s, *comment;

        int retval;

        retval = ds_get_line(ds, file);

        if (retval) {

            return retval;

        }

        s = ds_cstr(ds);

        if (*s == '#') {

            puts(s);

            continue;

        }

        comment = strchr(s, '#');

        if (comment) {

            *comment = '\0';

        }

        if (s[strspn(s, " \t\n")] == '\0') {

            putchar('\n');

            continue;

        }

        return 0;

    }

}

char *

ds_cstr(struct ds *ds)

{

    if (!ds->string) {

        ds_reserve(ds, 0);

    }

    ds->string[ds->length] = '\0';

    return ds->string;

}

const char *

ds_cstr_ro(const struct ds *ds)

{

    return ds_cstr(CONST_CAST(struct ds *, ds));

}

/* Returns a null-terminated string representing the current contents of 'ds',

 * which the caller is expected to free with free(), then clears the contents

 * of 'ds'. */

char *

ds_steal_cstr(struct ds *ds)

{

    char *s = ds_cstr(ds);

    ds_init(ds);

    return s;

}

void

ds_destroy(struct ds *ds)

{

    free(ds->string);

}

/* Swaps the content of 'a' and 'b'. */

void

ds_swap(struct ds *a, struct ds *b)

{

    struct ds temp = *a;

    *a = *b;

    *b = temp;

}

void

ds_put_hex(struct ds *ds, const void *buf_, size_t size)

{

    const uint8_t *buf = buf_;

    bool printed = false;

    int i;

    for (i = 0; i < size; i++) {

        uint8_t val = buf[i];

        if (val || printed) {

            if (!printed) {

                ds_put_format(ds, "0x%"PRIx8, val);

            } else {

                ds_put_format(ds, "%02"PRIx8, val);

            }

            printed = true;

        }

    }

    if (!printed) {

        ds_put_char(ds, '0');

    }

}

static void

ds_put_hex_dump__(struct ds *ds, const void *buf_, size_t size,

                  uintptr_t ofs, bool ascii, bool skip_zero_lines)

{

    const uint8_t *buf = buf_;

    const size_t per_line = 16; /* Maximum bytes per line. */

    while (size > 0) {

        size_t start, end, n;

        size_t i;

        /* Number of bytes on this line. */

        start = ofs % per_line;

        end = per_line;

        if (end - start > size)

            end = start + size;

        n = end - start;

        if (skip_zero_lines && is_all_zeros(&buf[start], n)) {

            goto next;

        }

        /* Print line. */

        ds_put_format(ds, "%08"PRIxMAX"  ",

                      (uintmax_t) ROUND_DOWN(ofs, per_line));

        for (i = 0; i < start; i++) {

            ds_put_format(ds, "   ");

        }

        for (; i < end; i++) {

            ds_put_format(ds, "%02x%c",

                          buf[i - start], i == per_line / 2 - 1? '-' : ' ');

        }

        if (ascii) {

            for (; i < per_line; i++)

                ds_put_format(ds, "   ");

            ds_put_format(ds, "|");

            for (i = 0; i < start; i++)

                ds_put_format(ds, " ");

            for (; i < end; i++) {

                int c = buf[i - start];

                ds_put_char(ds, c >= 32 && c < 127 ? c : '.');

            }

            for (; i < per_line; i++)

                ds_put_format(ds, " ");

            ds_put_format(ds, "|");

        } else {

            ds_chomp(ds, ' ');

        }

        ds_put_format(ds, "\n");

next:

        ofs += n;

        buf += n;

        size -= n;

    }

}

/* Writes the 'size' bytes in 'buf' to 'string' as hex bytes arranged 16 per

 * line.  Numeric offsets are also included, starting at 'ofs' for the first

 * byte in 'buf'.  If 'ascii' is true then the corresponding ASCII characters

 * are also rendered alongside. */

void

ds_put_hex_dump(struct ds *ds, const void *buf_, size_t size,

                uintptr_t ofs, bool ascii)

{

    ds_put_hex_dump__(ds, buf_, size, ofs, ascii, false);

}

/* Same as 'ds_put_hex_dump', but doesn't print lines that only contains

 * zero bytes. */

void

ds_put_sparse_hex_dump(struct ds *ds, const void *buf_, size_t size,

                       uintptr_t ofs, bool ascii)

{

    ds_put_hex_dump__(ds, buf_, size, ofs, ascii, true);

}

int

ds_last(const struct ds *ds)

{

    return ds->length > 0 ? (unsigned char) ds->string[ds->length - 1] : EOF;

}

bool

ds_chomp(struct ds *ds, int c)

{

    if (ds->length > 0 && ds->string[ds->length - 1] == (char) c) {

        ds->string[--ds->length] = '\0';

        return true;

    } else {

        return false;

    }

}

void

ds_clone(struct ds *dst, struct ds *source)

{

    if (!source->allocated) {

        ds_init(dst);

        return;

    }

    dst->length = source->length;

    dst->allocated = dst->length;

    dst->string = xmalloc(dst->allocated + 1);

    memcpy(dst->string, source->string, dst->allocated + 1);

}