encode.c File Reference

#include "postgres.h"
#include <ctype.h>
#include "mb/pg_wchar.h"
#include "utils/builtins.h"
#include "utils/memutils.h"
#include "varatt.h"

Include dependency graph for encode.c:

Go to the source code of this file.

Data Structures
struct	pg_encoding

Macros
#define	VAL(CH)   ((CH) - '0')
#define	DIG(VAL)   ((VAL) + '0')

Functions
static const struct pg_encoding *	pg_find_encoding (const char *name)
Datum	binary_encode (PG_FUNCTION_ARGS)
Datum	binary_decode (PG_FUNCTION_ARGS)
uint64	hex_encode (const char *src, size_t len, char *dst)
static bool	get_hex (const char *cp, char *out)
uint64	hex_decode (const char *src, size_t len, char *dst)
uint64	hex_decode_safe (const char *src, size_t len, char *dst, Node *escontext)
static uint64	hex_enc_len (const char *src, size_t srclen)
static uint64	hex_dec_len (const char *src, size_t srclen)
static uint64	pg_base64_encode (const char *src, size_t len, char *dst)
static uint64	pg_base64_decode (const char *src, size_t len, char *dst)
static uint64	pg_base64_enc_len (const char *src, size_t srclen)
static uint64	pg_base64_dec_len (const char *src, size_t srclen)
static uint64	esc_encode (const char *src, size_t srclen, char *dst)
static uint64	esc_decode (const char *src, size_t srclen, char *dst)
static uint64	esc_enc_len (const char *src, size_t srclen)
static uint64	esc_dec_len (const char *src, size_t srclen)

Variables
static const char	hextbl [] = "0123456789abcdef"
static const int8	hexlookup [128]
static const char	_base64 []
static const int8	b64lookup [128]
struct {
const char *   name
struct pg_encoding   enc
}	enclist []

Macro Definition Documentation

DIG

#define DIG

(

VAL

)

((VAL) + '0')

Definition at line 412 of file encode.c.

VAL

#define VAL

(

CH

)

((CH) - '0')

Definition at line 411 of file encode.c.

Function Documentation

binary_decode()

Datum binary_decode

(

PG_FUNCTION_ARGS

)

Definition at line 96 of file encode.c.

{
    text       *data = PG_GETARG_TEXT_PP(0);
    Datum       name = PG_GETARG_DATUM(1);
    bytea      *result;
    char       *namebuf;
    char       *dataptr;
    size_t      datalen;
    uint64      resultlen;
    uint64      res;
    const struct pg_encoding *enc;
 
    namebuf = TextDatumGetCString(name);
 
    enc = pg_find_encoding(namebuf);
    if (enc == NULL)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("unrecognized encoding: \"%s\"", namebuf)));
 
    dataptr = VARDATA_ANY(data);
    datalen = VARSIZE_ANY_EXHDR(data);
 
    resultlen = enc->decode_len(dataptr, datalen);
 
    /*
     * resultlen possibly overflows uint32, therefore on 32-bit machines it's
     * unsafe to rely on palloc's internal check.
     */
    if (resultlen > MaxAllocSize - VARHDRSZ)
        ereport(ERROR,
                (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
                 errmsg("result of decoding conversion is too large")));
 
    result = palloc(VARHDRSZ + resultlen);
 
    res = enc->decode(dataptr, datalen, VARDATA(result));
 
    /* Make this FATAL 'cause we've trodden on memory ... */
    if (res > resultlen)
        elog(FATAL, "overflow - decode estimate too small");
 
    SET_VARSIZE(result, VARHDRSZ + res);
 
    PG_RETURN_BYTEA_P(result);
}

References data, pg_encoding::decode, pg_encoding::decode_len, elog(), enc, ereport, errcode(), errmsg(), ERROR, FATAL, MaxAllocSize, name, palloc(), pg_find_encoding(), PG_GETARG_DATUM, PG_GETARG_TEXT_PP, PG_RETURN_BYTEA_P, res, SET_VARSIZE, TextDatumGetCString, VARDATA, VARDATA_ANY, VARHDRSZ, and VARSIZE_ANY_EXHDR.

binary_encode()

Datum binary_encode

(

PG_FUNCTION_ARGS

)

Definition at line 48 of file encode.c.

{
    bytea      *data = PG_GETARG_BYTEA_PP(0);
    Datum       name = PG_GETARG_DATUM(1);
    text       *result;
    char       *namebuf;
    char       *dataptr;
    size_t      datalen;
    uint64      resultlen;
    uint64      res;
    const struct pg_encoding *enc;
 
    namebuf = TextDatumGetCString(name);
 
    enc = pg_find_encoding(namebuf);
    if (enc == NULL)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("unrecognized encoding: \"%s\"", namebuf)));
 
    dataptr = VARDATA_ANY(data);
    datalen = VARSIZE_ANY_EXHDR(data);
 
    resultlen = enc->encode_len(dataptr, datalen);
 
    /*
     * resultlen possibly overflows uint32, therefore on 32-bit machines it's
     * unsafe to rely on palloc's internal check.
     */
    if (resultlen > MaxAllocSize - VARHDRSZ)
        ereport(ERROR,
                (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
                 errmsg("result of encoding conversion is too large")));
 
    result = palloc(VARHDRSZ + resultlen);
 
    res = enc->encode(dataptr, datalen, VARDATA(result));
 
    /* Make this FATAL 'cause we've trodden on memory ... */
    if (res > resultlen)
        elog(FATAL, "overflow - encode estimate too small");
 
    SET_VARSIZE(result, VARHDRSZ + res);
 
    PG_RETURN_TEXT_P(result);
}

References data, elog(), enc, pg_encoding::encode, pg_encoding::encode_len, ereport, errcode(), errmsg(), ERROR, FATAL, MaxAllocSize, name, palloc(), pg_find_encoding(), PG_GETARG_BYTEA_PP, PG_GETARG_DATUM, PG_RETURN_TEXT_P, res, SET_VARSIZE, TextDatumGetCString, VARDATA, VARDATA_ANY, VARHDRSZ, and VARSIZE_ANY_EXHDR.

esc_dec_len()

static uint64 esc_dec_len ( const char *  src, size_t  srclen  )

static

Definition at line 523 of file encode.c.

{
    const char *end = src + srclen;
    uint64      len = 0;
 
    while (src < end)
    {
        if (src[0] != '\\')
            src++;
        else if (src + 3 < end &&
                 (src[1] >= '0' && src[1] <= '3') &&
                 (src[2] >= '0' && src[2] <= '7') &&
                 (src[3] >= '0' && src[3] <= '7'))
        {
            /*
             * backslash + valid octal
             */
            src += 4;
        }
        else if (src + 1 < end &&
                 (src[1] == '\\'))
        {
            /*
             * two backslashes = backslash
             */
            src += 2;
        }
        else
        {
            /*
             * one backslash, not followed by ### valid octal
             */
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
                     errmsg("invalid input syntax for type %s", "bytea")));
        }
 
        len++;
    }
    return len;
}

References ereport, errcode(), errmsg(), ERROR, and len.

esc_decode()

static uint64 esc_decode ( const char *  src, size_t  srclen, char *  dst  )

static

Definition at line 454 of file encode.c.

{
    const char *end = src + srclen;
    char       *rp = dst;
    uint64      len = 0;
 
    while (src < end)
    {
        if (src[0] != '\\')
            *rp++ = *src++;
        else if (src + 3 < end &&
                 (src[1] >= '0' && src[1] <= '3') &&
                 (src[2] >= '0' && src[2] <= '7') &&
                 (src[3] >= '0' && src[3] <= '7'))
        {
            int         val;
 
            val = VAL(src[1]);
            val <<= 3;
            val += VAL(src[2]);
            val <<= 3;
            *rp++ = val + VAL(src[3]);
            src += 4;
        }
        else if (src + 1 < end &&
                 (src[1] == '\\'))
        {
            *rp++ = '\\';
            src += 2;
        }
        else
        {
            /*
             * One backslash, not followed by ### valid octal. Should never
             * get here, since esc_dec_len does same check.
             */
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
                     errmsg("invalid input syntax for type %s", "bytea")));
        }
 
        len++;
    }
 
    return len;
}

References ereport, errcode(), errmsg(), ERROR, len, VAL, and val.

esc_enc_len()

static uint64 esc_enc_len ( const char *  src, size_t  srclen  )

static

Definition at line 502 of file encode.c.

{
    const char *end = src + srclen;
    uint64      len = 0;
 
    while (src < end)
    {
        if (*src == '\0' || IS_HIGHBIT_SET(*src))
            len += 4;
        else if (*src == '\\')
            len += 2;
        else
            len++;
 
        src++;
    }
 
    return len;
}

References IS_HIGHBIT_SET, and len.

esc_encode()

static uint64 esc_encode ( const char *  src, size_t  srclen, char *  dst  )

static

Definition at line 415 of file encode.c.

{
    const char *end = src + srclen;
    char       *rp = dst;
    uint64      len = 0;
 
    while (src < end)
    {
        unsigned char c = (unsigned char) *src;
 
        if (c == '\0' || IS_HIGHBIT_SET(c))
        {
            rp[0] = '\\';
            rp[1] = DIG(c >> 6);
            rp[2] = DIG((c >> 3) & 7);
            rp[3] = DIG(c & 7);
            rp += 4;
            len += 4;
        }
        else if (c == '\\')
        {
            rp[0] = '\\';
            rp[1] = '\\';
            rp += 2;
            len += 2;
        }
        else
        {
            *rp++ = c;
            len++;
        }
 
        src++;
    }
 
    return len;
}

References DIG, IS_HIGHBIT_SET, and len.

get_hex()

static bool get_hex ( const char *  cp, char *  out  )

inlinestatic

Definition at line 176 of file encode.c.

{
    unsigned char c = (unsigned char) *cp;
    int         res = -1;
 
    if (c < 127)
        res = hexlookup[c];
 
    *out = (char) res;
 
    return (res >= 0);
}

References hexlookup, and res.

Referenced by hex_decode_safe().

hex_dec_len()

static uint64 hex_dec_len ( const char *  src, size_t  srclen  )

static

Definition at line 243 of file encode.c.

{
    return (uint64) srclen >> 1;
}

hex_decode()

uint64 hex_decode	(	const char *	src,
		size_t	len,
		char *	dst
	)

Definition at line 190 of file encode.c.

{
    return hex_decode_safe(src, len, dst, NULL);
}

References hex_decode_safe(), and len.

hex_decode_safe()

uint64 hex_decode_safe	(	const char *	src,
		size_t	len,
		char *	dst,
		Node *	escontext
	)

Definition at line 196 of file encode.c.

{
    const char *s,
               *srcend;
    char        v1,
                v2,
               *p;
 
    srcend = src + len;
    s = src;
    p = dst;
    while (s < srcend)
    {
        if (*s == ' ' || *s == '\n' || *s == '\t' || *s == '\r')
        {
            s++;
            continue;
        }
        if (!get_hex(s, &v1))
            ereturn(escontext, 0,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("invalid hexadecimal digit: \"%.*s\"",
                            pg_mblen(s), s)));
        s++;
        if (s >= srcend)
            ereturn(escontext, 0,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("invalid hexadecimal data: odd number of digits")));
        if (!get_hex(s, &v2))
            ereturn(escontext, 0,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("invalid hexadecimal digit: \"%.*s\"",
                            pg_mblen(s), s)));
        s++;
        *p++ = (v1 << 4) | v2;
    }
 
    return p - dst;
}

References ereturn, errcode(), errmsg(), get_hex(), len, and pg_mblen().

Referenced by byteain(), and hex_decode().

hex_enc_len()

static uint64 hex_enc_len ( const char *  src, size_t  srclen  )

static

Definition at line 237 of file encode.c.

{
    return (uint64) srclen << 1;
}

hex_encode()

uint64 hex_encode	(	const char *	src,
		size_t	len,
		char *	dst
	)

Definition at line 162 of file encode.c.

{
    const char *end = src + len;
 
    while (src < end)
    {
        *dst++ = hextbl[(*src >> 4) & 0xF];
        *dst++ = hextbl[*src & 0xF];
        src++;
    }
    return (uint64) len * 2;
}

References hextbl, and len.

Referenced by AddFileToBackupManifest(), byteaout(), and SendBackupManifest().

pg_base64_dec_len()

static uint64 pg_base64_dec_len ( const char *  src, size_t  srclen  )

static

Definition at line 392 of file encode.c.

{
    return ((uint64) srclen * 3) >> 2;
}

pg_base64_decode()

static uint64 pg_base64_decode ( const char *  src, size_t  len, char *  dst  )

static

Definition at line 314 of file encode.c.

{
    const char *srcend = src + len,
               *s = src;
    char       *p = dst;
    char        c;
    int         b = 0;
    uint32      buf = 0;
    int         pos = 0,
                end = 0;
 
    while (s < srcend)
    {
        c = *s++;
 
        if (c == ' ' || c == '\t' || c == '\n' || c == '\r')
            continue;
 
        if (c == '=')
        {
            /* end sequence */
            if (!end)
            {
                if (pos == 2)
                    end = 1;
                else if (pos == 3)
                    end = 2;
                else
                    ereport(ERROR,
                            (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                             errmsg("unexpected \"=\" while decoding base64 sequence")));
            }
            b = 0;
        }
        else
        {
            b = -1;
            if (c > 0 && c < 127)
                b = b64lookup[(unsigned char) c];
            if (b < 0)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                         errmsg("invalid symbol \"%.*s\" found while decoding base64 sequence",
                                pg_mblen(s - 1), s - 1)));
        }
        /* add it to buffer */
        buf = (buf << 6) + b;
        pos++;
        if (pos == 4)
        {
            *p++ = (buf >> 16) & 255;
            if (end == 0 || end > 1)
                *p++ = (buf >> 8) & 255;
            if (end == 0 || end > 2)
                *p++ = buf & 255;
            buf = 0;
            pos = 0;
        }
    }
 
    if (pos != 0)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("invalid base64 end sequence"),
                 errhint("Input data is missing padding, is truncated, or is otherwise corrupted.")));
 
    return p - dst;
}

References b, b64lookup, buf, ereport, errcode(), errhint(), errmsg(), ERROR, len, and pg_mblen().

pg_base64_enc_len()

static uint64 pg_base64_enc_len ( const char *  src, size_t  srclen  )

static

Definition at line 385 of file encode.c.

{
    /* 3 bytes will be converted to 4, linefeed after 76 chars */
    return ((uint64) srclen + 2) / 3 * 4 + (uint64) srclen / (76 * 3 / 4);
}

pg_base64_encode()

static uint64 pg_base64_encode ( const char *  src, size_t  len, char *  dst  )

static

Definition at line 267 of file encode.c.

{
    char       *p,
               *lend = dst + 76;
    const char *s,
               *end = src + len;
    int         pos = 2;
    uint32      buf = 0;
 
    s = src;
    p = dst;
 
    while (s < end)
    {
        buf |= (unsigned char) *s << (pos << 3);
        pos--;
        s++;
 
        /* write it out */
        if (pos < 0)
        {
            *p++ = _base64[(buf >> 18) & 0x3f];
            *p++ = _base64[(buf >> 12) & 0x3f];
            *p++ = _base64[(buf >> 6) & 0x3f];
            *p++ = _base64[buf & 0x3f];
 
            pos = 2;
            buf = 0;
        }
        if (p >= lend)
        {
            *p++ = '\n';
            lend = p + 76;
        }
    }
    if (pos != 2)
    {
        *p++ = _base64[(buf >> 18) & 0x3f];
        *p++ = _base64[(buf >> 12) & 0x3f];
        *p++ = (pos == 0) ? _base64[(buf >> 6) & 0x3f] : '=';
        *p++ = '=';
    }
 
    return p - dst;
}

References _base64, buf, and len.

pg_find_encoding()

static const struct pg_encoding * pg_find_encoding ( const char *  name )

static

Definition at line 603 of file encode.c.

{
    int         i;
 
    for (i = 0; enclist[i].name; i++)
        if (pg_strcasecmp(enclist[i].name, name) == 0)
            return &enclist[i].enc;
 
    return NULL;
}

References enclist, i, name, and pg_strcasecmp().

Referenced by binary_decode(), and binary_encode().

Variable Documentation

_base64

const char _base64[]

static

Initial value:

=
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"

Definition at line 252 of file encode.c.

Referenced by pg_base64_encode().

b64lookup

const int8 b64lookup[128]

static

Initial value:

= {
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
    -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
    -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
}

Definition at line 255 of file encode.c.

Referenced by pg_base64_decode().

enc

struct pg_encoding enc

Definition at line 571 of file encode.c.

Referenced by binary_decode(), and binary_encode().

const { ... } enclist[]

Initial value:

=
 
{
    {
        "hex",
        {
            hex_enc_len, hex_dec_len, hex_encode, hex_decode
        }
    },
    {
        "base64",
        {
            pg_base64_enc_len, pg_base64_dec_len, pg_base64_encode, pg_base64_decode
        }
    },
    {
        "escape",
        {
            esc_enc_len, esc_dec_len, esc_encode, esc_decode
        }
    },
    {
        NULL,
        {
            NULL, NULL, NULL, NULL
        }
    }
}

Referenced by pg_find_encoding().

hexlookup

const int8 hexlookup[128]

static

Initial value:

= {
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1,
    -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
}

Definition at line 150 of file encode.c.

Referenced by get_hex().

hextbl

const char hextbl[] = "0123456789abcdef"

static

Definition at line 148 of file encode.c.

Referenced by hex_encode().

name

const char* name

Definition at line 571 of file encode.c.

Referenced by binary_decode(), binary_encode(), and pg_find_encoding().