ip2region_private/maker/java/src/org/lionsoul/ip2region/DbSearcher.java

406 lines
12 KiB
Java

package org.lionsoul.ip2region;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
/**
* ip db searcher class (Not thread safe)
*
* @author chenxin<chenxin619315@gmail.com>
*/
public class DbSearcher
{
public static final int BTREE_ALGORITHM = 1;
public static final int BINARY_ALGORITHM = 2;
public static final int MEMORY_ALGORITYM = 3;
/**
* db config
*/
private DbConfig dbConfig = null;
/**
* db file access handler
*/
private RandomAccessFile raf = null;
/**
* header blocks buffer
*/
private long[] HeaderSip = null;
private int[] HeaderPtr = null;
private int headerLength;
/**
* super blocks info
*/
private long firstIndexPtr = 0;
private long lastIndexPtr = 0;
private int totalIndexBlocks = 0;
/**
* for memory mode
* the original db binary string
*/
private byte[] dbBinStr = null;
/**
* construct class
*
* @param bdConfig
* @param dbFile
* @throws FileNotFoundException
*/
public DbSearcher( DbConfig dbConfig, String dbFile ) throws FileNotFoundException
{
this.dbConfig = dbConfig;
raf = new RandomAccessFile(dbFile, "r");
}
/**
* construct method with self-define std ip2region bianry string support
* Thanks to the issue from Wendal at https://gitee.com/lionsoul/ip2region/issues/IILFL
*
* @param dbConfig
* @param dbBinStr
*/
public DbSearcher(DbConfig dbConfig, byte[] dbBinStr)
{
this.dbConfig = dbConfig;
this.dbBinStr = dbBinStr;
firstIndexPtr = Util.getIntLong(dbBinStr, 0);
lastIndexPtr = Util.getIntLong(dbBinStr, 4);
totalIndexBlocks = (int)((lastIndexPtr - firstIndexPtr)/IndexBlock.getIndexBlockLength()) + 1;
}
/**
* get the region with a int ip address with memory binary search algorithm
*
* @param ip
* @throws IOException
*/
public DataBlock memorySearch(long ip) throws IOException
{
int blen = IndexBlock.getIndexBlockLength();
if ( dbBinStr == null ) {
dbBinStr = new byte[(int)raf.length()];
raf.seek(0L);
raf.readFully(dbBinStr, 0, dbBinStr.length);
//initialize the global vars
firstIndexPtr = Util.getIntLong(dbBinStr, 0);
lastIndexPtr = Util.getIntLong(dbBinStr, 4);
totalIndexBlocks = (int)((lastIndexPtr - firstIndexPtr)/blen) + 1;
}
//search the index blocks to define the data
int l = 0, h = totalIndexBlocks;
long sip, eip, dataptr = 0;
while ( l <= h ) {
int m = (l + h) >> 1;
int p = (int)(firstIndexPtr + m * blen);
sip = Util.getIntLong(dbBinStr, p);
if ( ip < sip ) {
h = m - 1;
} else {
eip = Util.getIntLong(dbBinStr, p + 4);
if ( ip > eip ) {
l = m + 1;
} else {
dataptr = Util.getIntLong(dbBinStr, p + 8);
break;
}
}
}
//not matched
if ( dataptr == 0 ) return null;
//get the data
int dataLen = (int)((dataptr >> 24) & 0xFF);
int dataPtr = (int)((dataptr & 0x00FFFFFF));
int city_id = (int)Util.getIntLong(dbBinStr, dataPtr);
String region = new String(dbBinStr, dataPtr + 4, dataLen - 4, "UTF-8");
return new DataBlock(city_id, region, dataPtr);
}
/**
* get the region throught the ip address with memory binary search algorithm
*
* @param ip
* @return DataBlock
* @throws IOException
*/
public DataBlock memorySearch( String ip ) throws IOException
{
return memorySearch(Util.ip2long(ip));
}
/**
* get by index ptr
*
* @param indexPtr
* @throws IOException
*/
public DataBlock getByIndexPtr( long ptr ) throws IOException
{
raf.seek(ptr);
byte[] buffer = new byte[12];
raf.readFully(buffer, 0, buffer.length);
//long startIp = Util.getIntLong(buffer, 0);
//long endIp = Util.getIntLong(buffer, 4);
long extra = Util.getIntLong(buffer, 8);
int dataLen = (int)((extra >> 24) & 0xFF);
int dataPtr = (int)((extra & 0x00FFFFFF));
raf.seek(dataPtr);
byte[] data = new byte[dataLen];
raf.readFully(data, 0, data.length);
int city_id = (int)Util.getIntLong(data, 0);
String region = new String(data, 4, data.length - 4, "UTF-8");
return new DataBlock(city_id, region, dataPtr);
}
/**
* get the region with a int ip address with b-tree algorithm
*
* @param ip
* @throws IOException
*/
public DataBlock btreeSearch( long ip ) throws IOException
{
//check and load the header
if ( HeaderSip == null ) {
raf.seek(8L); //pass the super block
byte[] b = new byte[dbConfig.getTotalHeaderSize()];
// byte[] b = new byte[4096];
raf.readFully(b, 0, b.length);
//fill the header
int len = b.length >> 3, idx = 0; //b.lenght / 8
HeaderSip = new long[len];
HeaderPtr = new int [len];
long startIp, dataPtr;
for ( int i = 0; i < b.length; i += 8 ) {
startIp = Util.getIntLong(b, i);
dataPtr = Util.getIntLong(b, i + 4);
if ( dataPtr == 0 ) break;
HeaderSip[idx] = startIp;
HeaderPtr[idx] = (int)dataPtr;
idx++;
}
headerLength = idx;
}
//1. define the index block with the binary search
if ( ip == HeaderSip[0] ) {
return getByIndexPtr(HeaderPtr[0]);
} else if ( ip == HeaderSip[headerLength-1] ) {
return getByIndexPtr(HeaderPtr[headerLength-1]);
}
int l = 0, h = headerLength, sptr = 0, eptr = 0;
while ( l <= h ) {
int m = (l + h) >> 1;
//perfetc matched, just return it
if ( ip == HeaderSip[m] ) {
if ( m > 0 ) {
sptr = HeaderPtr[m-1];
eptr = HeaderPtr[m ];
} else {
sptr = HeaderPtr[m ];
eptr = HeaderPtr[m+1];
}
break;
}
//less then the middle value
if ( ip < HeaderSip[m] ) {
if ( m == 0 ) {
sptr = HeaderPtr[m ];
eptr = HeaderPtr[m+1];
break;
} else if ( ip > HeaderSip[m-1] ) {
sptr = HeaderPtr[m-1];
eptr = HeaderPtr[m ];
break;
}
h = m - 1;
} else {
if ( m == headerLength - 1 ) {
sptr = HeaderPtr[m-1];
eptr = HeaderPtr[m ];
break;
} else if ( ip <= HeaderSip[m+1] ) {
sptr = HeaderPtr[m ];
eptr = HeaderPtr[m+1];
break;
}
l = m + 1;
}
}
//match nothing just stop it
if ( sptr == 0 ) return null;
//2. search the index blocks to define the data
int blockLen = eptr - sptr, blen = IndexBlock.getIndexBlockLength();
byte[] iBuffer = new byte[blockLen + blen]; //include the right border block
raf.seek(sptr);
raf.readFully(iBuffer, 0, iBuffer.length);
l = 0; h = blockLen / blen;
long sip, eip, dataptr = 0;
while ( l <= h ) {
int m = (l + h) >> 1;
int p = m * blen;
sip = Util.getIntLong(iBuffer, p);
if ( ip < sip ) {
h = m - 1;
} else {
eip = Util.getIntLong(iBuffer, p + 4);
if ( ip > eip ) {
l = m + 1;
} else {
dataptr = Util.getIntLong(iBuffer, p + 8);
break;
}
}
}
//not matched
if ( dataptr == 0 ) return null;
//3. get the data
int dataLen = (int)((dataptr >> 24) & 0xFF);
int dataPtr = (int)((dataptr & 0x00FFFFFF));
raf.seek(dataPtr);
byte[] data = new byte[dataLen];
raf.readFully(data, 0, data.length);
int city_id = (int)Util.getIntLong(data, 0);
String region = new String(data, 4, data.length - 4, "UTF-8");
return new DataBlock(city_id, region, dataPtr);
}
/**
* get the region throught the ip address with b-tree search algorithm
*
* @param ip
* @return DataBlock
* @throws IOException
*/
public DataBlock btreeSearch( String ip ) throws IOException
{
return btreeSearch(Util.ip2long(ip));
}
/**
* get the region with a int ip address with binary search algorithm
*
* @param ip
* @throws IOException
*/
public DataBlock binarySearch( long ip ) throws IOException
{
int blen = IndexBlock.getIndexBlockLength();
if ( totalIndexBlocks == 0 ) {
raf.seek(0L);
byte[] superBytes = new byte[8];
raf.readFully(superBytes, 0, superBytes.length);
//initialize the global vars
firstIndexPtr = Util.getIntLong(superBytes, 0);
lastIndexPtr = Util.getIntLong(superBytes, 4);
totalIndexBlocks = (int)((lastIndexPtr - firstIndexPtr)/blen) + 1;
}
//search the index blocks to define the data
int l = 0, h = totalIndexBlocks;
byte[] buffer = new byte[blen];
long sip, eip, dataptr = 0;
while ( l <= h ) {
int m = (l + h) >> 1;
raf.seek(firstIndexPtr + m * blen); //set the file pointer
raf.readFully(buffer, 0, buffer.length);
sip = Util.getIntLong(buffer, 0);
if ( ip < sip ) {
h = m - 1;
} else {
eip = Util.getIntLong(buffer, 4);
if ( ip > eip ) {
l = m + 1;
} else {
dataptr = Util.getIntLong(buffer, 8);
break;
}
}
}
//not matched
if ( dataptr == 0 ) return null;
//get the data
int dataLen = (int)((dataptr >> 24) & 0xFF);
int dataPtr = (int)((dataptr & 0x00FFFFFF));
raf.seek(dataPtr);
byte[] data = new byte[dataLen];
raf.readFully(data, 0, data.length);
int city_id = (int)Util.getIntLong(data, 0);
String region = new String(data, 4, data.length - 4, "UTF-8");
return new DataBlock(city_id, region, dataPtr);
}
/**
* get the region throught the ip address with binary search algorithm
*
* @param ip
* @return DataBlock
* @throws IOException
*/
public DataBlock binarySearch( String ip ) throws IOException
{
return binarySearch(Util.ip2long(ip));
}
/**
* get the db config
*
* @return DbConfig
*/
public DbConfig getDbConfig()
{
return dbConfig;
}
/**
* close the db
*
* @throws IOException
*/
public void close() throws IOException
{
HeaderSip = null; //let gc do its work
HeaderPtr = null;
dbBinStr = null;
raf.close();
}
}