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RelAccX class

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Thulinma 2016-12-30 23:16:34 +01:00
parent 3307e2a492
commit 1138303b40
2 changed files with 469 additions and 1 deletions
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369
lib/util.cpp
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@ -2,9 +2,22 @@
#define _FILE_OFFSET_BITS 64
#include "util.h"
#include "timing.h"
#include "defines.h"
#include "bitfields.h"
#include <stdio.h>
#include <iostream>
#define RECORD_POINTER p+getOffset()+(getRecordPosition(recordNo)*getRSize())+fd.offset
#define RAXHDR_FIELDOFFSET p[1]
#define RAXHDR_RECORDCNT *(uint32_t*)(p+2)
#define RAXHDR_RECORDSIZE *(uint32_t*)(p+6)
#define RAXHDR_STARTPOS *(uint32_t*)(p+10)
#define RAXHDR_DELETED *(uint64_t*)(p+14)
#define RAXHDR_PRESENT *(uint32_t*)(p+22)
#define RAXHDR_OFFSET *(uint16_t*)(p+26)
#define RAX_REQDFIELDS_LEN 28
namespace Util{
bool stringScan(const std::string & src, const std::string & pattern, std::deque<std::string> & result){
result.clear();
@ -53,6 +66,362 @@ namespace Util {
return fseeko(stream, offset, whence);
}
///If waitReady is true (default), waits for isReady() to return true in 50ms sleep increments.
RelAccX::RelAccX(char * data, bool waitReady){
if (!data){
p = 0;
return;
}
p = data;
if (waitReady){
while (!isReady()){Util::sleep(50);}
}
if (isReady()){
uint16_t offset = RAXHDR_FIELDOFFSET;
if (offset < 11 || offset >= getOffset()){
FAIL_MSG("Invalid field offset: %u", offset);
p = 0;
return;
}
uint32_t dataOffset = 0;
while (offset < getOffset()){
const uint8_t sizeByte = p[offset];
const uint8_t nameLen = sizeByte >> 3;
const uint8_t typeLen = sizeByte & 0x7;
const uint8_t fieldType = p[offset+1+nameLen];
const std::string fieldName(p+offset+1, nameLen);
uint32_t size = 0;
switch (typeLen){
case 1://derived from field type
if ((fieldType & 0xF0) == RAX_UINT || (fieldType & 0xF0) == RAX_INT){
//Integer types - lower 4 bits +1 are size in bytes
size = (fieldType & 0x0F) + 1;
}else{
if ((fieldType & 0xF0) == RAX_STRING || (fieldType & 0xF0) == RAX_RAW){
//String types - 8*2^(lower 4 bits) is size in bytes
size = 16 << (fieldType & 0x0F);
}else{
WARN_MSG("Unhandled field type!");
}
}
break;
//Simple sizes in bytes
case 2: size = p[offset+1+nameLen+1]; break;
case 3: size = *(uint16_t*)(p+offset+1+nameLen+1); break;
case 4:
size = Bit::btoh24(p+offset+1+nameLen+1);
break;
case 5: size = *(uint32_t*)(p+offset+1+nameLen+1); break;
default:
WARN_MSG("Unhandled field data size!");
break;
}
fields[fieldName] = RelAccXFieldData(fieldType, size, dataOffset);
DONTEVEN_MSG("Field %s: type %u, size %lu, offset %lu", fieldName.c_str(), fieldType, size, dataOffset);
dataOffset += size;
offset += nameLen + typeLen + 1;
}
}
}
///Gets the amount of records present in the structure.
uint32_t RelAccX::getRCount() const{return RAXHDR_RECORDCNT;}
///Gets the size in bytes of a single record in the structure.
uint32_t RelAccX::getRSize() const{return RAXHDR_RECORDSIZE;}
///Gets the position in the records where the entries start
uint32_t RelAccX::getStartPos() const{return RAXHDR_STARTPOS;}
///Gets the number of deleted records
uint64_t RelAccX::getDeleted() const{return RAXHDR_DELETED;}
///Gets the number of records present
///Defaults to the record count if set to zero.
uint32_t RelAccX::getPresent() const{return (RAXHDR_PRESENT ? RAXHDR_PRESENT : RAXHDR_RECORDCNT);}
///Gets the offset from the structure start where records begin.
uint16_t RelAccX::getOffset() const{return *(uint16_t*)(p+26);}
///Returns true if the structure is ready for read operations.
bool RelAccX::isReady() const{return p && (p[0] & 1);}
///Returns true if the structure will no longer be updated.
bool RelAccX::isExit() const{return !p || (p[0] & 2);}
///Returns true if the structure should be reloaded through out of band means.
bool RelAccX::isReload() const{return p[0] & 4;}
///Returns true if the given record number can be accessed.
bool RelAccX::isRecordAvailable(uint64_t recordNo) const{
//Check if the record has been deleted
if (getDeleted() > recordNo){return false;}
//Check if the record hasn't been created yet
if (recordNo - getDeleted() >= getPresent()){return false;}
return true;
}
///Converts the given record number into an offset of records after getOffset()'s offset.
///Does no bounds checking whatsoever, allowing access to not-yet-created or already-deleted records.
///This access method is stable with changing start/end positions and present record counts, because it only
///depends on the record count, which may not change for ring buffers.
uint32_t RelAccX::getRecordPosition(uint64_t recordNo) const{
if (getRCount()){
return recordNo % getRCount();
}else{
return recordNo;
}
}
///Returns the (max) size of the given field.
///For string types, returns the exact size excluding terminating null byte.
///For other types, returns the maximum size possible.
///Returns 0 if the field does not exist.
uint32_t RelAccX::getSize(const std::string & name, uint64_t recordNo) const{
if (!fields.count(name) || !isRecordAvailable(recordNo)){return 0;}
const RelAccXFieldData & fd = fields.at(name);
if ((fd.type & 0xF0) == RAX_STRING){
return strnlen(RECORD_POINTER, fd.size);
}else{
return fd.size;
}
}
///Returns a pointer to the given field in the given record number.
///Returns a null pointer if the field does not exist.
char * RelAccX::getPointer(const std::string & name, uint64_t recordNo) const{
if (!fields.count(name)){return 0;}
const RelAccXFieldData & fd = fields.at(name);
return RECORD_POINTER;
}
///Returns the value of the given integer-type field in the given record, as an uint64_t type.
///Returns 0 if the field does not exist or is not an integer type.
uint64_t RelAccX::getInt(const std::string & name, uint64_t recordNo) const{
if (!fields.count(name)){return 0;}
const RelAccXFieldData & fd = fields.at(name);
char * ptr = RECORD_POINTER;
if ((fd.type & 0xF0) == RAX_UINT){//unsigned int
switch (fd.size){
case 1: return *(uint8_t*)ptr;
case 2: return *(uint16_t*)ptr;
case 3: return Bit::btoh24(ptr);
case 4: return *(uint32_t*)ptr;
case 8: return *(uint64_t*)ptr;
default: WARN_MSG("Unimplemented integer");
}
}
if ((fd.type & 0xF0) == RAX_INT){//signed int
switch (fd.size){
case 1: return *(int8_t*)ptr;
case 2: return *(int16_t*)ptr;
case 3: return Bit::btoh24(ptr);
case 4: return *(int32_t*)ptr;
case 8: return *(int64_t*)ptr;
default: WARN_MSG("Unimplemented integer");
}
}
return 0; //Not an integer type, or not implemented
}
std::string RelAccX::toPrettyString() const{
std::stringstream r;
uint64_t delled = getDeleted();
uint64_t max = delled+getRCount();
r << "RelAccX: " << getRCount() << " x " << getRSize() << "b @" << getOffset() << " (#" << getDeleted() << " - #" << (getDeleted()+getPresent()-1) << ")" << std::endl;
for (uint64_t i = delled; i < max; ++i){
r << " #" << i << ":" << std::endl;
for (std::map<std::string, RelAccXFieldData>::const_iterator it = fields.begin(); it != fields.end(); ++it){
r << " " << it->first << ": ";
switch (it->second.type & 0xF0){
case RAX_INT: r << (int64_t)getInt(it->first, i) << std::endl; break;
case RAX_UINT: r << getInt(it->first, i) << std::endl; break;
case RAX_STRING: r << getPointer(it->first, i) << std::endl; break;
default: r << "[UNIMPLEMENTED]" << std::endl; break;
}
}
}
return r.str();
}
/// Returns the default size in bytes of the data component of a field type number.
/// Returns zero if not implemented, unknown or the type has no default.
uint32_t RelAccX::getDefaultSize(uint8_t fType){
if ((fType & 0XF0) == RAX_INT || (fType & 0XF0) == RAX_UINT){
return (fType & 0x0F) + 1;//Default size is lower 4 bits plus one bytes
}
if ((fType & 0XF0) == RAX_STRING || (fType & 0XF0) == RAX_RAW){
return 16 << (fType & 0x0F);//Default size is 16 << (lower 4 bits) bytes
}
return 0;
}
/// Adds a new field to the internal list of fields.
/// Can only be called if not ready, exit or reload.
/// Changes the offset and record size to match.
/// Fails if called multiple times with the same field name.
void RelAccX::addField(const std::string & name, uint8_t fType, uint32_t fLen){
if (isExit() || isReload() || isReady()){
WARN_MSG("Attempting to add a field to a non-writeable memory area");
return;
}
if (!name.size() || name.size() > 31){
WARN_MSG("Attempting to add a field with illegal name: %s (%u chars)", name.c_str(), name.size());
return;
}
//calculate fLen if missing
if (!fLen){
fLen = getDefaultSize(fType);
if (!fLen){
WARN_MSG("Attempting to add a mandatory-size field without size");
return;
}
}
//We now know for sure fLen is set
//Get current offset and record size
uint16_t & offset = RAXHDR_OFFSET;
uint32_t & recSize = RAXHDR_RECORDSIZE;
//The first field initializes the offset and record size.
if (!fields.size()){
recSize = 0;//Nothing yet, this is the first data field.
offset = RAX_REQDFIELDS_LEN;//All mandatory fields are first - so we start there.
RAXHDR_FIELDOFFSET = offset;//store the field_offset
}
uint8_t typeLen = 1;
//Check if fLen is a non-default value
if (getDefaultSize(fType) != fLen){
//Calculate the smallest size integer we can fit this in
typeLen = 5;//32 bit
if (fLen < 0x10000){typeLen = 3;}//16 bit
if (fLen < 0x100){typeLen = 2;}//8 bit
}
//store the details for internal use
//recSize is the field offset, since we haven't updated it yet
fields[name] = RelAccXFieldData(fType, fLen, recSize);
//write the data to memory
p[offset] = (name.size() << 3) | (typeLen & 0x7);
memcpy(p+offset+1, name.data(), name.size());
p[offset+1+name.size()] = fType;
if (typeLen == 2){*(uint8_t*)(p+offset+2+name.size()) = fLen;}
if (typeLen == 3){*(uint16_t*)(p+offset+2+name.size()) = fLen;}
if (typeLen == 5){*(uint32_t*)(p+offset+2+name.size()) = fLen;}
//Calculate new offset and record size
offset += 1+name.size()+typeLen;
recSize += fLen;
}
///Sets the record counter to the given value.
void RelAccX::setRCount(uint32_t count){RAXHDR_RECORDCNT = count;}
///Sets the position in the records where the entries start
void RelAccX::setStartPos(uint32_t n){RAXHDR_STARTPOS = n;}
///Sets the number of deleted records
void RelAccX::setDeleted(uint64_t n){RAXHDR_DELETED = n;}
///Sets the number of records present
///Defaults to the record count if set to zero.
void RelAccX::setPresent(uint32_t n){RAXHDR_PRESENT = n;}
///Sets the ready flag.
///After calling this function, addField() may no longer be called.
///Fails if exit, reload or ready are (already) set.
void RelAccX::setReady(){
if (isExit() || isReload() || isReady()){
WARN_MSG("Could not set ready on structure with pre-existing state");
return;
}
p[0] |= 1;
}
//Sets the exit flag.
///After calling this function, addField() may no longer be called.
void RelAccX::setExit(){p[0] |= 2;}
//Sets the reload flag.
///After calling this function, addField() may no longer be called.
void RelAccX::setReload(){p[0] |= 4;}
///Writes the given string to the given field in the given record.
///Fails if ready is not set.
///Ensures the last byte is always a zero.
void RelAccX::setString(const std::string & name, const std::string & val, uint64_t recordNo){
if (!fields.count(name)){
WARN_MSG("Setting non-existent string %s", name.c_str());
return;
}
const RelAccXFieldData & fd = fields.at(name);
if ((fd.type & 0xF0) != RAX_STRING){
WARN_MSG("Setting non-string %s", name.c_str());
return;
}
char * ptr = RECORD_POINTER;
memcpy(ptr, val.data(), std::min((uint32_t)val.size(), fd.size));
ptr[std::min((uint32_t)val.size(), fd.size-1)] = 0;
}
///Writes the given int to the given field in the given record.
///Fails if ready is not set or the field is not an integer type.
void RelAccX::setInt(const std::string & name, uint64_t val, uint64_t recordNo){
if (!fields.count(name)){
WARN_MSG("Setting non-existent integer %s", name.c_str());
return;
}
const RelAccXFieldData & fd = fields.at(name);
char * ptr = RECORD_POINTER;
if ((fd.type & 0xF0) == RAX_UINT){//unsigned int
switch (fd.size){
case 1: *(uint8_t*)ptr = val; return;
case 2: *(uint16_t*)ptr = val; return;
case 3: Bit::htob24(ptr, val); return;
case 4: *(uint32_t*)ptr = val; return;
case 8: *(uint64_t*)ptr = val; return;
default: WARN_MSG("Unimplemented integer size %u", fd.size); return;
}
}
if ((fd.type & 0xF0) == RAX_INT){//signed int
switch (fd.size){
case 1: *(int8_t*)ptr = (int64_t)val; return;
case 2: *(int16_t*)ptr = (int64_t)val; return;
case 3: Bit::htob24(ptr, val); return;
case 4: *(int32_t*)ptr = (int64_t)val; return;
case 8: *(int64_t*)ptr = (int64_t)val; return;
default: WARN_MSG("Unimplemented integer size %u", fd.size); return;
}
}
WARN_MSG("Setting non-integer %s", name.c_str());
}
///Updates the deleted record counter, the start position and the present record counter, shifting the ring buffer start position forward without moving the ring buffer end position.
///If the records present counter would be pushed into the negative by this function, sets it to zero, defaulting it to the record count for all relevant purposes.
void RelAccX::deleteRecords(uint32_t amount){
uint32_t & startPos = RAXHDR_STARTPOS;
uint64_t & deletedRecs = RAXHDR_DELETED;
uint32_t & recsPresent = RAXHDR_PRESENT;
startPos += amount;//update start position
deletedRecs += amount;//update deleted record counter
if (recsPresent >= amount){
recsPresent -= amount;//decrease records present
}else{
recsPresent = 0;
}
}
///Updates the present record counter, shifting the ring buffer end position forward without moving the ring buffer start position.
///If the records present counter would be pushed past the record counter by this function, sets it to zero, defaulting it to the record count for all relevant purposes.
void RelAccX::addRecords(uint32_t amount){
uint32_t & recsPresent = RAXHDR_PRESENT;
uint32_t & recordsCount = RAXHDR_RECORDCNT;
if (recsPresent+amount > recordsCount){
recsPresent = 0;
}else{
recsPresent += amount;
}
}
}

99
lib/util.h
View file

@ -1,9 +1,108 @@
#include <string>
#include <deque>
#include <map>
#include <stdint.h>
namespace Util {
bool stringScan(const std::string & src, const std::string & pattern, std::deque<std::string> & result);
uint64_t ftell(FILE * stream);
uint64_t fseek(FILE * stream, uint64_t offset, int whence);
///Holds type, size and offset for RelAccX class internal data fields.
class RelAccXFieldData{
public:
uint8_t type;
uint32_t size;
uint32_t offset;
RelAccXFieldData(){}
RelAccXFieldData(uint8_t t, uint32_t s, uint32_t o){
type = t;
size = s;
offset = o;
}
};
#define RAX_NESTED 0x01
#define RAX_UINT 0x10
#define RAX_INT 0x20
#define RAX_16UINT 0x11
#define RAX_16INT 0x21
#define RAX_32UINT 0x13
#define RAX_32INT 0x23
#define RAX_64UINT 0x17
#define RAX_64INT 0x27
#define RAX_STRING 0x30
#define RAX_32STRING 0x31
#define RAX_64STRING 0x32
#define RAX_128STRING 0x33
#define RAX_256STRING 0x34
#define RAX_RAW 0x40
/// Reliable Access class.
/// Provides reliable access to memory data structures, using dynamic static offsets and a status field.
/// All internal fields are host byte order (since no out-of-machine accesses happen), except 24 bit fields, which are network byte order.
/// Data structure:
/// 1 byte status bit fields (1 = ready, 2 = exit, 4 = reload)
/// 1 byte field_offset (where the field description starts)
/// 4 bytes record count - number of records present
/// 4 bytes record size - bytes per record
/// 4 bytes record startpos - position of record where ring starts
/// 8 bytes records deleted - amount of records no longer present
/// 4 bytes records present - amount of record currently present
/// 2 bytes record offset
/// @field_offset: offset-field_offset bytes fields:
/// 5 bits field name len (< 32), 3 bits type len (1-5)
/// len bytes field name string (< 32 bytes)
/// 1 byte field type (0x01 = RelAccX, 0x1X = uint, 0x2X = int, 0x3X = string, 0x4X = binary)
/// if type-len > 1: rest-of-type-len bytes max len
/// else, for 0xYX:
/// Y=1/2: X+1 bytes maxlen (1-16b)
/// Y=3/4: (16 << X) bytes maxlen (16b-256kb)
/// record count * record size bytes, in field order:
/// 0x01: RelAccX record
/// 0x1X/2X: X+1 bytes (u)int data
/// 0x3X: max maxlen bytes string data, zero term'd
/// 0x4X: maxlen bytes binary data
/// Setting ready means the record size, offset and fields will no longer change. Count may still go up (not down)
/// Setting exit means the writer has exited, and readers should exit too.
/// Setting reload means the writer needed to change fields, and the pointer should be closed and re-opened through outside means (e.g. closing and re-opening the containing shm page).
class RelAccX{
public:
RelAccX(char * data, bool waitReady = true);
//Read-only functions:
uint32_t getRCount() const;
uint32_t getRSize() const;
uint16_t getOffset() const;
uint32_t getStartPos() const;
uint64_t getDeleted() const;
uint32_t getPresent() const;
bool isReady() const;
bool isExit() const;
bool isReload() const;
bool isRecordAvailable(uint64_t recordNo) const;
uint32_t getRecordPosition(uint64_t recordNo) const;
uint32_t getSize(const std::string & name, uint64_t recordNo=0) const;
char * getPointer(const std::string & name, uint64_t recordNo=0) const;
uint64_t getInt(const std::string & name, uint64_t recordNo=0) const;
std::string toPrettyString() const;
//Read-write functions:
void addField(const std::string & name, uint8_t fType, uint32_t fLen=0);
void setRCount(uint32_t count);
void setStartPos(uint32_t n);
void setDeleted(uint64_t n);
void setPresent(uint32_t n);
void setReady();
void setExit();
void setReload();
void setString(const std::string & name, const std::string & val, uint64_t recordNo=0);
void setInt(const std::string & name, uint64_t val, uint64_t recordNo=0);
void deleteRecords(uint32_t amount);
void addRecords(uint32_t amount);
protected:
static uint32_t getDefaultSize(uint8_t fType);
private:
char * p;
std::map<std::string, RelAccXFieldData> fields;
};
}