/**
* Appends `n_bytes' to the pmsg_t buffer. If the last pmsg_t is writable
* it is filled with as much data as space is still available. Otherwise
* or if this space is not sufficient another pmsg_t is created and
* appendded to the list.
*/
void
pmsg_slist_append(slist_t *slist, const void *data, size_t n_bytes)
{
pmsg_t *mb;
g_assert(slist);
if (0 == n_bytes)
return;
g_assert(NULL != data);
mb = slist_tail(slist);
if (mb && pmsg_is_writable(mb)) {
size_t n;
n = pmsg_write(mb, data, n_bytes);
data = (const char *) data + n;
n_bytes -= n;
}
if (n_bytes > 0) {
mb = pmsg_new(PMSG_P_DATA, NULL, MAX(n_bytes, PMSG_SLIST_GROW_MIN));
pmsg_write(mb, data, n_bytes);
slist_append(slist, mb);
}
}
/**
* Open stream to PDU message buffer.
*
* Stream must be closed with ostream_close().
*/
ostream_t *
ostream_open_pmsg(pmsg_t *mb)
{
ostream_t *os;
g_assert(mb != NULL);
g_assert(pmsg_is_writable(mb));
os = ostream_alloc(OSTREAM_T_PMSG);
os->u.mb = mb;
return os;
}
/**
* Write NUL-terminated string.
*
* If (size_t) -1 is given as length, then it is computed via strlen(), in
* which case the string buffer must be NUL-terminated. Otherwise, the value
* is taken to be the pre-computed string length.
*
* The string is written as: <ule64(length)><bytes>, no trailing NUL.
*/
void
pmsg_write_string(pmsg_t *mb, const char *str, size_t length)
{
size_t len;
g_assert(pmsg_is_writable(mb)); /* Not shared, or would corrupt data */
len = (size_t) -1 == length ? strlen(str) : length;
g_assert(UNSIGNED(pmsg_available(mb)) >= len + 10); /* Need ule64 length */
pmsg_write_ule64(mb, (uint64) len);
if (len != 0) {
pmsg_write(mb, str, len);
}
}
/**
* Write NUL-terminated string, up to `n' characters or the first seen NUL
* in the buffer, whichever comes first.
*
* The string is written as: <ule64(length)><bytes>, no trailing NUL.
*/
void
pmsg_write_fixed_string(pmsg_t *mb, const char *str, size_t n)
{
size_t len;
g_assert(pmsg_is_writable(mb)); /* Not shared, or would corrupt data */
g_assert(UNSIGNED(pmsg_available(mb)) >= n + 10); /* Need ule64 length */
len = strlen(str);
len = MIN(n, len);
pmsg_write_ule64(mb, (uint64) len);
if (len != 0) {
pmsg_write(mb, str, len);
}
}
/**
* @return amount of data that can be written at the end of the message.
*/
int
pmsg_writable_length(const pmsg_t *mb)
{
pdata_t *arena;
int available;
pmsg_check_consistency(mb);
/*
* If buffer is not writable (shared among several readers), it is
* forbidden to write any new data to it.
*/
arena = mb->m_data;
available = arena->d_end - mb->m_wptr;
return pmsg_is_writable(mb) ? available : 0;
}
/**
* Write an unsigned 64-bit quantity using variable length encoding (little
* endian). Each serialized byte contains 7 bits, the highest bit is set when
* this is the last byte of the encoded value.
*/
void
pmsg_write_ule64(pmsg_t *mb, uint64 v)
{
uint64 value = v;
g_assert(pmsg_is_writable(mb)); /* Not shared, or would corrupt data */
g_assert(pmsg_available(mb) >= 10); /* Will need 10 bytes at most */
do {
uint8 byt = (uint8) (value & 0x7f); /* Lowest 7 bits */
value >>= 7;
if (0 == value) {
byt |= 0x80; /* Last byte emitted */
}
pmsg_write_u8(mb, byt);
} while (value != 0);
}
/**
* Write NUL-terminated string, up to `n' characters or the first seen NUL
* in the buffer, whichever comes first.
*
* The string is written as: <ule64(length)><bytes>, no trailing NUL.
*/
void
pmsg_write_fixed_string(pmsg_t *mb, const char *str, size_t n)
{
size_t len;
g_assert(pmsg_is_writable(mb)); /* Not shared, or would corrupt data */
g_assert(UNSIGNED(pmsg_available(mb)) >= n + 10); /* Need ule64 length */
g_assert_log(size_is_non_negative(n), "%s(): n=%zd", G_STRFUNC, n);
len = vstrlen(str);
len = MIN(n, len);
pmsg_write_ule64(mb, (uint64) len);
if (len != 0) {
pmsg_write(mb, str, len);
}
}
/**
* Shift back unread data to the beginning of the buffer.
*/
void
pmsg_compact(pmsg_t *mb)
{
int shifting;
pmsg_check_consistency(mb);
g_assert(pmsg_is_writable(mb)); /* Not shared, or would corrupt data */
g_assert(mb->m_rptr <= mb->m_wptr);
shifting = mb->m_rptr - mb->m_data->d_arena;
g_assert(shifting >= 0);
if (shifting != 0) {
memmove(mb->m_data->d_arena, mb->m_rptr, pmsg_size(mb));
mb->m_rptr -= shifting;
mb->m_wptr -= shifting;
}
}
/**
* Write NUL-terminated string.
*
* If (size_t) -1 is given as length, then it is computed via strlen(), in
* which case the string buffer must be NUL-terminated. Otherwise, the value
* is taken to be the pre-computed string length.
*
* The string is written as: <ule64(length)><bytes>, no trailing NUL.
*/
void
pmsg_write_string(pmsg_t *mb, const char *str, size_t length)
{
size_t len;
g_assert(pmsg_is_writable(mb)); /* Not shared, or would corrupt data */
g_assert_log(size_is_non_negative(length) || (size_t) -1 == length,
"%s(): length=%zd", G_STRFUNC, length);
len = (size_t) -1 == length ? strlen(str) : length;
g_assert(UNSIGNED(pmsg_available(mb)) >= len + 10); /* Need ule64 length */
pmsg_write_ule64(mb, (uint64) len);
if (len != 0) {
pmsg_write(mb, str, len);
}
}
/**
* Write data at the end of the message.
* The message must be the only reference to the underlying data.
*
* @returns amount of written data.
*/
int
pmsg_write(pmsg_t *mb, const void *data, int len)
{
pdata_t *arena;
int available, written;
pmsg_check_consistency(mb);
g_assert(pmsg_is_writable(mb)); /* Not shared, or would corrupt data */
arena = mb->m_data;
available = arena->d_end - mb->m_wptr;
g_assert(available >= 0); /* Data cannot go beyond end of arena */
written = len >= available ? available : len;
if (written != 0)
mb->m_wptr = mempcpy(mb->m_wptr, data, written);
return written;
}
/**
* Copy ``len'' bytes from the source message block to the destination by
* reading the source bytes and writing them to the recipient.
*
* @returns amount of bytes written, which may be lower than the requested
* amount if the source buffer was shorter or there is not enough room in
* the destination.
*/
int
pmsg_copy(pmsg_t *dest, pmsg_t *src, int len)
{
int copied, available;
pmsg_check_consistency(dest);
pmsg_check_consistency(src);
g_assert(pmsg_is_writable(dest)); /* Not shared, or would corrupt data */
copied = src->m_wptr - src->m_rptr; /* Available data in source */
copied = MIN(copied, len);
available = pmsg_available(dest); /* Room in destination buffer */
copied = MIN(copied, available);
if (copied > 0) {
dest->m_wptr = mempcpy(dest->m_wptr, src->m_rptr, copied);
src->m_rptr += copied;
}
return copied;
}
/**
* Write an IPv4 or IPv6 address.
*/
void
pmsg_write_ipv4_or_ipv6_addr(pmsg_t *mb, host_addr_t addr)
{
g_assert(pmsg_is_writable(mb)); /* Not shared, or would corrupt data */
g_assert(pmsg_available(mb) >= 17);
switch (host_addr_net(addr)) {
case NET_TYPE_IPV4:
pmsg_write_u8(mb, 4);
pmsg_write_be32(mb, host_addr_ipv4(addr));
break;
case NET_TYPE_IPV6:
pmsg_write_u8(mb, 16);
pmsg_write(mb, host_addr_ipv6(&addr), 16);
break;
case NET_TYPE_LOCAL:
case NET_TYPE_NONE:
g_error("unexpected address in pmsg_write_ipv4_or_ipv6_addr(): %s",
host_addr_to_string(addr));
}
}
/**
* Shift back unread data to the beginning of the buffer if that can make
* at least 1/nth of the total arena size available for writing.
*/
void
pmsg_fractional_compact(pmsg_t *mb, int n)
{
int shifting;
g_assert(n > 0);
pmsg_check_consistency(mb);
g_assert(pmsg_is_writable(mb)); /* Not shared, or would corrupt data */
g_assert(mb->m_rptr <= mb->m_wptr);
shifting = mb->m_rptr - mb->m_data->d_arena;
g_assert(shifting >= 0);
if (shifting != 0) {
unsigned available = pmsg_available(mb) + shifting;
if (available >= pmsg_phys_len(mb) / n) {
memmove(mb->m_data->d_arena, mb->m_rptr, pmsg_size(mb));
mb->m_rptr -= shifting;
mb->m_wptr -= shifting;
}
}
}
