serval-dna/overlay_buffer.c

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C
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2011-12-21 09:55:05 +00:00
/*
Serval Distributed Numbering Architecture (DNA)
Copyright (C) 2010 Paul Gardner-Stephen
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <assert.h>
#include "serval.h"
#include "conf.h"
#include "mem.h"
#include "overlay_buffer.h"
/*
When writing to a buffer, sizeLimit may place an upper bound on the amount of space to use
When reading from a buffer, sizeLimit should first be set to the length of any existing data.
In either case, functions that don't take an offset use and advance the position.
*/
struct overlay_buffer *_ob_new(struct __sourceloc __whence)
{
struct overlay_buffer *ret = emalloc_zero(sizeof(struct overlay_buffer));
DEBUGF(overlaybuffer, "ob_new() return %p", ret);
if (ret == NULL)
return NULL;
ob_unlimitsize(ret);
return ret;
}
// index an existing static buffer.
// and allow other callers to use the ob_ convenience methods for reading and writing up to size bytes.
struct overlay_buffer *_ob_static(struct __sourceloc __whence, unsigned char *bytes, size_t size)
{
struct overlay_buffer *ret = emalloc_zero(sizeof(struct overlay_buffer));
DEBUGF(overlaybuffer, "ob_static(bytes=%p, size=%zu) return %p", bytes, size, ret);
if (ret == NULL)
return NULL;
ret->bytes = bytes;
ret->allocSize = size;
ret->allocated = NULL;
ob_unlimitsize(ret);
return ret;
}
// create a new overlay buffer from an existing piece of another buffer.
// Both buffers will point to the same memory region.
// It is up to the caller to ensure this buffer is not used after the parent buffer is freed.
struct overlay_buffer *_ob_slice(struct __sourceloc __whence, struct overlay_buffer *b, size_t offset, size_t length)
{
if (offset + length > b->allocSize) {
WHY("Buffer isn't long enough to slice");
return NULL;
}
struct overlay_buffer *ret = emalloc_zero(sizeof(struct overlay_buffer));
DEBUGF(overlaybuffer, "ob_slice(b=%p, offset=%zu, length=%zu) return %p", b, offset, length, ret);
if (ret == NULL)
return NULL;
ret->bytes = b->bytes + offset;
ret->allocSize = length;
ret->allocated = NULL;
ob_unlimitsize(ret);
return ret;
}
struct overlay_buffer *_ob_dup(struct __sourceloc __whence, struct overlay_buffer *b)
{
struct overlay_buffer *ret = emalloc_zero(sizeof(struct overlay_buffer));
DEBUGF(overlaybuffer, "ob_dup(b=%p) return %p", b, ret);
if (ret == NULL)
return NULL;
ret->sizeLimit = b->sizeLimit;
ret->position = b->position;
ret->checkpointLength = b->checkpointLength;
if (b->bytes && b->allocSize){
// duplicate any bytes that might be relevant
size_t byteCount = b->position;
if (b->sizeLimit != SIZE_MAX) {
assert(b->position <= b->sizeLimit);
byteCount = b->sizeLimit;
}
if (byteCount > b->allocSize)
byteCount = b->allocSize;
if (byteCount)
ob_append_bytes(ret, b->bytes, byteCount);
}
return ret;
}
void _ob_free(struct __sourceloc __whence, struct overlay_buffer *b)
{
assert(b != NULL);
DEBUGF(overlaybuffer, "ob_free(b=%p)", b);
if (b->allocated)
free(b->allocated);
free(b);
}
int _ob_checkpoint(struct __sourceloc __whence, struct overlay_buffer *b)
{
assert(b != NULL);
b->checkpointLength = b->position;
DEBUGF(overlaybuffer, "ob_checkpoint(b=%p) checkpointLength=%zu", b, b->checkpointLength);
return 0;
}
int _ob_rewind(struct __sourceloc __whence, struct overlay_buffer *b)
{
assert(b != NULL);
b->position = b->checkpointLength;
DEBUGF(overlaybuffer, "ob_rewind(b=%p) position=%zu", b, b->position);
return 0;
}
void _ob_limitsize(struct __sourceloc __whence, struct overlay_buffer *b, size_t bytes)
{
assert(b != NULL);
assert(bytes != SIZE_MAX);
assert(b->position <= bytes);
assert(b->checkpointLength <= bytes);
if (b->bytes && b->allocated == NULL)
assert(bytes <= b->allocSize);
b->sizeLimit = bytes;
DEBUGF(overlaybuffer, "ob_limitsize(b=%p, bytes=%zu) sizeLimit=%zu", b, bytes, b->sizeLimit);
}
void _ob_unlimitsize(struct __sourceloc __whence, struct overlay_buffer *b)
{
assert(b != NULL);
b->sizeLimit = SIZE_MAX;
DEBUGF(overlaybuffer, "ob_unlimitsize(b=%p) sizeLimit=%zu", b, b->sizeLimit);
}
void _ob_flip(struct __sourceloc __whence, struct overlay_buffer *b)
{
DEBUGF(overlaybuffer, "ob_flip(b=%p) checkpointLength=0 position=0", b);
b->checkpointLength = 0;
ob_limitsize(b, b->position);
b->position = 0;
}
void _ob_clear(struct __sourceloc __whence, struct overlay_buffer *b)
{
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DEBUGF(overlaybuffer, "ob_clear(b=%p) checkpointLength=0 position=0", b);
b->checkpointLength = 0;
b->position = 0;
ob_unlimitsize(b);
}
/* Return 1 if space is available, 0 if not.
*/
ssize_t _ob_makespace(struct __sourceloc __whence, struct overlay_buffer *b, size_t bytes)
{
assert(b != NULL);
DEBUGF(overlaybuffer, "ob_makespace(b=%p, bytes=%zd) b->bytes=%p b->position=%zu b->allocSize=%zu",
b, bytes, b->bytes, b->position, b->allocSize);
if (b->position)
assert(b->bytes != NULL);
if (b->position + bytes > b->sizeLimit) {
DEBUGF(overlaybuffer, "ob_makespace(): asked for space to %zu, beyond size limit of %zu", b->position + bytes, b->sizeLimit);
return 0;
}
if (b->position + bytes <= b->allocSize)
return 1;
// Don't realloc a static buffer.
if (b->bytes && b->allocated == NULL) {
DEBUGF(overlaybuffer, "ob_makespace(): asked for space to %zu, beyond static buffer size of %zu", b->position + bytes, b->allocSize);
return 0;
}
size_t newSize = b->position + bytes;
if (newSize<64) newSize=64;
if (newSize&63) newSize+=64-(newSize&63);
if (newSize>1024 && (newSize&1023))
newSize+=1024-(newSize&1023);
if (newSize>65536 && (newSize&65535))
newSize+=65536-(newSize&65535);
if (newSize > b->sizeLimit)
newSize = b->sizeLimit;
assert(newSize >= b->position + bytes);
DEBUGF(overlaybuffer, "realloc(b->bytes=%p, newSize=%zu)", b->bytes, newSize);
unsigned char *new = emalloc(newSize);
if (!new)
return 0;
if (b->position)
bcopy(b->bytes,new,b->position);
if (b->allocated) {
assert(b->allocated == b->bytes);
free(b->allocated);
}
b->bytes=new;
b->allocated=new;
b->allocSize=newSize;
return 1;
}
/*
Functions that append data and increase the size of the buffer if possible / required
*/
void _ob_append_byte(struct __sourceloc __whence, struct overlay_buffer *b, unsigned char byte)
{
const int bytes = 1;
assert(b != NULL);
if (ob_makespace(b, bytes)) {
assert(b->bytes != NULL);
assert(b->position < b->allocSize);
b->bytes[b->position] = byte;
DEBUGF(overlaybuffer, "ob_append_byte(b=%p, byte=0x%02x) %p[%zd]=%02x position=%zu", b, byte, b->bytes, b->position, byte, b->position + bytes);
} else {
DEBUGF(overlaybuffer, "ob_append_byte(b=%p, byte=0x%02x) OVERRUN position=%zu", b, byte, b->position + bytes);
}
b->position += bytes;
}
unsigned char *_ob_append_space(struct __sourceloc __whence, struct overlay_buffer *b, size_t count)
{
assert(count > 0);
unsigned char *r = ob_makespace(b, count) ? &b->bytes[b->position] : NULL;
b->position += count;
DEBUGF(overlaybuffer, "ob_append_space(b=%p, count=%zu) position=%zu return %p", b, count, b->position, r);
return r;
}
void _ob_append_bytes(struct __sourceloc __whence, struct overlay_buffer *b, const unsigned char *bytes, size_t count)
{
assert(count > 0);
unsigned char *r = ob_makespace(b, count) ? &b->bytes[b->position] : NULL;
if (r) {
bcopy(bytes, r, count);
DEBUGF(overlaybuffer, "ob_append_bytes(b=%p, bytes=%p, count=%zu) position=%zu return %p", b, bytes, count, b->position + count, r);
} else {
DEBUGF(overlaybuffer, "ob_append_bytes(b=%p, bytes=%p, count=%zu) OVERRUN position=%zu return NULL", b, bytes, count, b->position + count);
}
if (IF_DEBUG(overlaybuffer))
dump("{overlaybuffer} ob_append_bytes", bytes, count);
b->position += count;
}
void _ob_append_str(struct __sourceloc whence, struct overlay_buffer *b, const char *str)
{
_ob_append_bytes(whence, b, (const uint8_t*)str, strlen(str)+1);
}
void _ob_append_ui16(struct __sourceloc __whence, struct overlay_buffer *b, uint16_t v)
{
const int bytes = 2;
if (ob_makespace(b, bytes)) {
b->bytes[b->position] = (v >> 8) & 0xFF;
b->bytes[b->position+1] = v & 0xFF;
DEBUGF(overlaybuffer, "ob_append_ui16(b=%p, v=%u) %p[%zd]=%s position=%zu", b, v, b->bytes, b->position, alloca_tohex(&b->bytes[b->position], bytes), b->position + bytes);
} else {
DEBUGF(overlaybuffer, "ob_append_ui16(b=%p, v=%u) OVERRUN position=%zu", b, v, b->position + bytes);
}
b->position += bytes;
}
void _ob_append_ui16_rv(struct __sourceloc __whence, struct overlay_buffer *b, uint16_t v)
{
const int bytes = 2;
if (ob_makespace(b, bytes)) {
b->bytes[b->position] = v & 0xFF;
b->bytes[b->position+1] = (v >> 8) & 0xFF;
DEBUGF(overlaybuffer, "ob_append_ui16(b=%p, v=%u) %p[%zd]=%s position=%zu", b, v, b->bytes, b->position, alloca_tohex(&b->bytes[b->position], bytes), b->position + bytes);
} else {
DEBUGF(overlaybuffer, "ob_append_ui16(b=%p, v=%u) OVERRUN position=%zu", b, v, b->position + bytes);
}
b->position += bytes;
}
void _ob_append_ui32(struct __sourceloc __whence, struct overlay_buffer *b, uint32_t v)
{
const int bytes = 4;
if (ob_makespace(b, bytes)) {
b->bytes[b->position] = (v >> 24) & 0xFF;
b->bytes[b->position+1] = (v >> 16) & 0xFF;
b->bytes[b->position+2] = (v >> 8) & 0xFF;
b->bytes[b->position+3] = v & 0xFF;
DEBUGF(overlaybuffer, "ob_append_ui32(b=%p, v=%"PRIu32") %p[%zd]=%s position=%zu",
b, v, b->bytes, b->position, alloca_tohex(&b->bytes[b->position], bytes), b->position + bytes);
} else {
DEBUGF(overlaybuffer, "ob_append_ui32(b=%p, v=%"PRIu32") OVERRUN position=%zu", b, v, b->position + bytes);
}
b->position += bytes;
}
void _ob_append_ui32_rv(struct __sourceloc __whence, struct overlay_buffer *b, uint32_t v)
{
const int bytes = 4;
if (ob_makespace(b, bytes)) {
b->bytes[b->position] = v & 0xFF;
b->bytes[b->position+1] = (v >> 8) & 0xFF;
b->bytes[b->position+2] = (v >> 16) & 0xFF;
b->bytes[b->position+3] = (v >> 24) & 0xFF;
DEBUGF(overlaybuffer, "ob_append_ui32(b=%p, v=%"PRIu32") %p[%zd]=%s position=%zu",
b, v, b->bytes, b->position, alloca_tohex(&b->bytes[b->position], bytes), b->position + bytes);
} else {
DEBUGF(overlaybuffer, "ob_append_ui32(b=%p, v=%"PRIu32") OVERRUN position=%zu", b, v, b->position + bytes);
}
b->position += bytes;
}
void _ob_append_ui64(struct __sourceloc __whence, struct overlay_buffer *b, uint64_t v)
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{
const int bytes = 8;
if (ob_makespace(b, bytes)) {
b->bytes[b->position] = (v >> 56) & 0xFF;
b->bytes[b->position+1] = (v >> 48) & 0xFF;
b->bytes[b->position+2] = (v >> 40) & 0xFF;
b->bytes[b->position+3] = (v >> 32) & 0xFF;
b->bytes[b->position+4] = (v >> 24) & 0xFF;
b->bytes[b->position+5] = (v >> 16) & 0xFF;
b->bytes[b->position+6] = (v >> 8) & 0xFF;
b->bytes[b->position+7] = v & 0xFF;
DEBUGF(overlaybuffer, "ob_append_ui64(b=%p, v=%"PRIu64") %p[%zd]=%s position=%zu",
b, v, b->bytes, b->position, alloca_tohex(&b->bytes[b->position], bytes), b->position + bytes);
} else {
DEBUGF(overlaybuffer, "ob_append_ui64(b=%p, v=%"PRIu64") OVERRUN position=%zu", b, v, b->position + bytes);
}
b->position += bytes;
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}
void _ob_append_ui64_rv(struct __sourceloc __whence, struct overlay_buffer *b, uint64_t v)
{
const int bytes = 8;
if (ob_makespace(b, bytes)) {
b->bytes[b->position] = v & 0xFF;
b->bytes[b->position+1] = (v >> 8) & 0xFF;
b->bytes[b->position+2] = (v >> 16) & 0xFF;
b->bytes[b->position+3] = (v >> 24) & 0xFF;
b->bytes[b->position+4] = (v >> 32) & 0xFF;
b->bytes[b->position+5] = (v >> 40) & 0xFF;
b->bytes[b->position+6] = (v >> 48) & 0xFF;
b->bytes[b->position+7] = (v >> 56) & 0xFF;
DEBUGF(overlaybuffer, "ob_append_ui64(b=%p, v=%"PRIu64") %p[%zd]=%s position=%zu",
b, v, b->bytes, b->position, alloca_tohex(&b->bytes[b->position], bytes), b->position + bytes);
} else {
DEBUGF(overlaybuffer, "ob_append_ui64(b=%p, v=%"PRIu64") OVERRUN position=%zu", b, v, b->position + bytes);
}
b->position += bytes;
}
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int measure_packed_uint(uint64_t v){
int ret=0;
do{
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v>>=7;
ret++;
}while(v);
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return ret;
}
int pack_uint(unsigned char *buffer, uint64_t v){
int ret=0;
do{
*buffer++=(v&0x7f) | (v>0x7f?0x80:0);
v>>=7;
ret++;
}while(v);
return ret;
}
int unpack_uint(unsigned char *buffer, int buff_size, uint64_t *v){
int i=0;
*v=0;
while(1){
if (i>=buff_size)
return -1;
char byte = buffer[i];
*v |= (byte&0x7f)<<(i*7);
i++;
if (!(byte&0x80))
break;
}
return i;
}
void _ob_append_packed_ui32(struct __sourceloc __whence, struct overlay_buffer *b, uint32_t v)
{
do {
ob_append_byte(b, (v&0x7f) | (v>0x7f?0x80:0));
v = v >> 7;
} while (v != 0);
}
void _ob_append_packed_ui64(struct __sourceloc __whence, struct overlay_buffer *b, uint64_t v)
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{
do {
ob_append_byte(b, (v&0x7f) | (v>0x7f?0x80:0));
v = v >> 7;
} while (v != 0);
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}
/*
Functions that read / write data within the existing length limit
*/
// make sure a range of bytes is valid for reading
static int test_offset(struct overlay_buffer *b, size_t length)
{
if (b->position + length > b->sizeLimit)
return -1;
if (b->position + length > b->allocSize)
return -1;
return 0;
}
// next byte without advancing
int ob_peek(struct overlay_buffer *b)
{
if (test_offset(b, 1))
return -1;
return b->bytes[b->position];
}
void ob_skip(struct overlay_buffer *b, unsigned n)
{
b->position += n;
}
// return a null terminated string pointer and advance past the string
const char *ob_get_str_ptr(struct overlay_buffer *b)
{
const char *ret = (const char*)(b->bytes + b->position);
off_t ofs=0;
while (test_offset(b, ofs)==0){
if (ret[ofs]=='\0'){
b->position+=ofs+1;
return ret;
}
ofs++;
}
return NULL;
}
int ob_get_bytes(struct overlay_buffer *b, unsigned char *buff, size_t len)
{
if (test_offset(b, len))
return -1;
bcopy(b->bytes + b->position, buff, len);
b->position+=len;
return 0;
}
unsigned char * ob_get_bytes_ptr(struct overlay_buffer *b, size_t len)
{
if (test_offset(b, len))
return NULL;
unsigned char *ret = b->bytes + b->position;
b->position+=len;
return ret;
}
uint32_t ob_get_ui32(struct overlay_buffer *b)
{
if (test_offset(b, 4))
return 0xFFFFFFFF; // ... unsigned
uint32_t ret = (unsigned)b->bytes[b->position] << 24
| b->bytes[b->position +1] << 16
| b->bytes[b->position +2] << 8
| b->bytes[b->position +3];
b->position+=4;
return ret;
}
uint32_t ob_get_ui32_rv(struct overlay_buffer *b)
{
if (test_offset(b, 4))
return 0xFFFFFFFF; // ... unsigned
uint32_t ret = b->bytes[b->position]
| b->bytes[b->position +1] << 8
| b->bytes[b->position +2] << 16
| (unsigned)b->bytes[b->position +3] << 24;
b->position+=4;
return ret;
}
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uint64_t ob_get_ui64(struct overlay_buffer *b)
{
if (test_offset(b, 8))
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return 0xFFFFFFFF; // ... unsigned
uint64_t ret = (uint64_t)b->bytes[b->position] << 56
| (uint64_t)b->bytes[b->position +1] << 48
| (uint64_t)b->bytes[b->position +2] << 40
| (uint64_t)b->bytes[b->position +3] << 36
| b->bytes[b->position +4] << 24
| b->bytes[b->position +5] << 16
| b->bytes[b->position +6] << 8
| b->bytes[b->position +7];
b->position+=8;
return ret;
}
uint64_t ob_get_ui64_rv(struct overlay_buffer *b)
{
if (test_offset(b, 8))
return 0xFFFFFFFF; // ... unsigned
uint64_t ret = (uint64_t)b->bytes[b->position]
| (uint64_t)b->bytes[b->position +1] << 8
| (uint64_t)b->bytes[b->position +2] << 16
| (uint64_t)b->bytes[b->position +3] << 24
| (uint64_t)b->bytes[b->position +4] << 32
| (uint64_t)b->bytes[b->position +5] << 40
| (uint64_t)b->bytes[b->position +6] << 48
| (uint64_t)b->bytes[b->position +7] << 56;
b->position+=8;
return ret;
}
uint16_t ob_get_ui16(struct overlay_buffer *b)
{
if (test_offset(b, 2))
return 0xFFFF; // ... unsigned
uint16_t ret = b->bytes[b->position] << 8
| b->bytes[b->position +1];
b->position+=2;
return ret;
}
uint16_t ob_get_ui16_rv(struct overlay_buffer *b)
{
if (test_offset(b, 2))
return 0xFFFF; // ... unsigned
uint16_t ret = b->bytes[b->position]
| b->bytes[b->position +1] << 8;
b->position+=2;
return ret;
}
uint32_t ob_get_packed_ui32(struct overlay_buffer *b)
{
uint32_t ret=0;
int shift=0;
int byte;
do{
byte = ob_get(b);
if (byte<0)
return WHY("Failed to unpack integer");
ret |= (byte&0x7f)<<shift;
shift+=7;
}while(byte & 0x80);
return ret;
}
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uint64_t ob_get_packed_ui64(struct overlay_buffer *b)
{
uint64_t ret=0;
int shift=0;
int byte;
do{
byte = ob_get(b);
if (byte<0)
return WHY("Failed to unpack integer");
ret |= (byte&0x7f)<<shift;
shift+=7;
}while(byte & 0x80);
return ret;
}
int ob_get(struct overlay_buffer *b)
{
if (test_offset(b, 1))
return -1;
return b->bytes[b->position++];
}
void _ob_set_ui16(struct __sourceloc __whence, struct overlay_buffer *b, size_t offset, uint16_t v)
{
const int bytes = 2;
assert(b != NULL);
assert(offset + bytes <= b->sizeLimit);
assert(offset + bytes <= b->allocSize);
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b->bytes[offset] = (v >> 8) & 0xFF;
b->bytes[offset+1] = v & 0xFF;
DEBUGF(overlaybuffer, "ob_set_ui16(b=%p, offset=%zd, v=%u) %p[%zd]=%s", b, offset, v, b->bytes, offset, alloca_tohex(&b->bytes[offset], bytes));
}
void _ob_set(struct __sourceloc __whence, struct overlay_buffer *b, size_t offset, unsigned char byte)
{
const int bytes = 1;
assert(b != NULL);
assert(offset + bytes <= b->sizeLimit);
assert(offset + bytes <= b->allocSize);
b->bytes[offset] = byte;
DEBUGF(overlaybuffer, "ob_set(b=%p, offset=%zd, byte=0x%02x) %p[%zd]=%s", b, offset, byte, b->bytes, offset, alloca_tohex(&b->bytes[offset], bytes));
}
size_t ob_position(struct overlay_buffer *b)
{
return b->position;
}
size_t ob_limit(struct overlay_buffer *b)
{
return b->sizeLimit;
}
size_t ob_remaining(struct overlay_buffer *b)
{
assert(b->sizeLimit != SIZE_MAX);
assert(b->position <= b->sizeLimit);
return (size_t)(b->sizeLimit - b->position);
}
int _ob_overrun(struct __sourceloc __whence, struct overlay_buffer *b)
{
int ret = b->position > (b->sizeLimit != SIZE_MAX && b->sizeLimit < b->allocSize ? b->sizeLimit : b->allocSize);
DEBUGF(overlaybuffer, "ob_overrun(b=%p) return %d", b, ret);
return ret;
}
unsigned char *ob_ptr(struct overlay_buffer *b)
{
return b->bytes;
}
unsigned char *ob_current_ptr(struct overlay_buffer *b)
{
return &b->bytes[b->position];
}
int asprintable(int c)
{
if (c<' ') return '.';
if (c>0x7e) return '.';
return c;
}
int ob_dump(struct overlay_buffer *b, char *desc)
{
_DEBUGF("overlay_buffer '%s' at %p (%p) : checkpoint=%zu, position=%zu, limit=%zu, size=%zu",
desc, b, b->bytes, b->checkpointLength, b->position, b->sizeLimit, b->allocSize);
if (b->bytes) {
if (b->sizeLimit != SIZE_MAX && b->sizeLimit > 0) {
assert(b->position <= b->sizeLimit);
dump(desc, b->bytes, b->sizeLimit);
} else if (b->position > 0)
dump(desc, b->bytes, b->position);
}
return 0;
}