--- /dev/null
+default: libpvector.a
+
+#.INTERMEDIATE: pvector.o
+pvector.o: CFLAGS = -Wall -g
+pvector.o: pvector.c | pvector.h
+
+libpvector.a: pvector.o
+ $(AR) r $@ $^
+CLEANRM += libpvector.a
+
+#.INTERMEDIATE: example-pvector.o
+example-pvector: CFLAGS = -Wall -g
+example-pvector: LDLIBS = libpvector.a
+example-pvector: example-pvector.o libpvector.a
+CLEANRM += example-pvector
+
+clean:
+ rm -f $(CLEANRM)
--- /dev/null
+127.0.0.0/8
+10.0.0.0/8
+196.168.0.0/16
--- /dev/null
+#include <arpa/inet.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include "pvector.h"
+
+typedef struct _ipslot {
+ char data[16];
+ unsigned int bits;
+} ipslot;
+
+static struct {
+ pvector data;
+ int fill;
+} table;
+
+#define BUFSZ 10000
+static struct {
+ char data[ BUFSZ ];
+ int cur;
+ int end;
+} stream;
+
+static int readline(int fd,char **outp) {
+ for ( ;; ) {
+ char *curp = stream.data + stream.cur;
+ char *endp = stream.data + stream.end;
+ char *top = curp;
+ while ( curp < endp ) {
+ if ( *(curp++) == '\n' ) {
+ stream.cur = curp - stream.data;
+ (*outp) = top;
+ return curp - top;
+ }
+ }
+ if ( top != stream.data ) {
+ curp = stream.data;
+ while ( top < endp ) {
+ *(curp++) = *(top++);
+ }
+ endp = curp;
+ stream.end = endp - stream.data;
+ }
+ stream.cur = 0;
+ ssize_t n = read( fd, endp, BUFSZ - stream.end );
+ if ( n <= 0 ) {
+ if ( stream.end == 0 ) {
+ return -1; // No more data
+ }
+ (*outp) = stream.data;
+ return stream.end;
+ }
+ stream.end += n;
+ }
+ //unreachable
+}
+
+// Scan to NUL, CR or c. Return pointer not including character.
+static char *scanto(char *p, char c) {
+ while ( *p && *p != '\n' && *p != c ) {
+ p++;
+ }
+ return p;
+}
+
+static int parse_addr(char *line,ipslot *addr) {
+ char *end = scanto( line, '\n' );
+ char *slash = scanto( line, '/' );
+ *slash = 0;
+ if ( inet_pton( AF_INET, line, addr->data ) == 0 ) {
+ addr->bits = 32;
+ } if ( inet_pton( AF_INET6, line, addr->data ) == 0 ) {
+ addr->bits = 128;
+ } else {
+ return 1;
+ }
+ if ( slash != end && sscanf( slash+1, "%u", &addr->bits ) != 1 ) {
+ return 1;
+ }
+ return 0;
+}
+
+static void add_entry(ipslot *tmp) {
+ ipslot *p = (ipslot *) malloc( sizeof( ipslot ) );
+ memmove( p, tmp, sizeof( ipslot ) );
+ if ( table.data.size == table.fill ) {
+ (void) pvector_resize( &table.data, table.fill + 256, 0 );
+ }
+ pvector_set( &table.data, table.fill++, p );
+}
+
+static void load_file(const char *filename) {
+ int fd = open( filename, O_RDONLY );
+ if ( fd < 0 ) {
+ perror( filename );
+ exit( errno );
+ }
+ char *line;
+ int n;
+ while ( ( n = readline( fd, &line ) ) >= 0 ) {
+ ipslot addr;
+ if ( parse_addr( line, &addr ) ) {
+ fprintf( stderr, "Bad address: %s\n", line );
+ continue;
+ }
+ add_entry( &addr );
+ }
+}
+
+static int int_reclaim(pvector *pv,int index,void *item) {
+ return 1;
+}
+
+
+int main(int argc,char **argv) {
+ pvector test;
+ pvector_resize( &test, 100, 0 );
+ pvector_set( &test, 5, (void*) 500 );
+ pvector_set( &test, 55, (void*) 600 );
+ //pvector_set( &test, 550, (void*) 800 );
+ pvector_resize( &test, 300, 0 );
+ pvector_set( &test, 55, (void*) 650 );
+ pvector_resize( &test, 30000, 0 );
+ pvector_set( &test, 22255, (void*) 26 );
+ pvector_resize( &test, 100, int_reclaim );
+ pvector_set( &test, 5, (void*) 2 );
+
+#if 0
+ int i;
+ for ( i = 1; i < argc; i++ ) {
+ load_file( argv[ i ] );
+ }
+#endif
+ return 0;
+}
--- /dev/null
+#include <stdlib.h>
+#include "pvector.h"
+
+/**
+ * Representing a vector of void* accessible via an indexing structure
+ * as levels of same-size pages. A "pvector_page" is a contiguous
+ * array of 256 void*.
+ */
+
+/**
+ * Advances a pvector index to the next used slot at or below the
+ * given level, starting from the indexed entry (inclusive) and up.
+ * The function will free any empty pages it discovers, and then
+ * update the index slots accordingly. The given index is advanced
+ * cyclically to match the found slot. The function returns a slot
+ * pointer to the used slot, if any, and 0 otherwise.
+ */
+static void **pvector_level_next_used(
+ pvector_page *page,unsigned int *index,int level,int end) {
+ void **p = (void**)&(*page)[ ((pvector_index*)index)->level[ level ] ];
+ for( ; *index < end; p++ ) {
+ if ( *p ) {
+ if ( level == 0 ) {
+ return p; // This is a used entry
+ }
+ // *p is an index that needs to be inspected recursively
+ int whole = ((pvector_index*)index)->level[ level - 1 ] == 0;
+ void **x = pvector_level_next_used( *p, index, level - 1, end );
+ if ( x ) {
+ return x; // Used slot was found; return it.
+ }
+ // The page *p is all empty, so can/should be reclaimed.
+ if ( whole ) {
+ free( *p );
+ *p = 0;
+ }
+ }
+ if ( ++(((pvector_index*)index)->level[ level ]) == 0 ) {
+ break; // cycling this level => nothing found
+ }
+ }
+ return 0;
+}
+
+// Find the next used slot at given index or later
+void **pvector_next_used(pvector *pv,unsigned int *index,
+ int (*reclaim)(pvector *,int,void*) )
+{
+ int levels = PV_LEVELS( pv->size );
+ while ( *index < pv->size ) {
+ void **slot = pvector_level_next_used(
+ pv->entries, index, levels - 1, pv->size ) ;
+ if ( slot && *slot ) {
+ if ( reclaim && reclaim( pv, *index, *slot ) == 0 ) {
+ *slot = 0;
+ } else {
+ return *slot;
+ }
+ }
+ (*index)++;
+ }
+ return 0;
+}
+
+// Reclaim tree of unused pages
+static void pvector_reclaim(pvector_page *page) {
+ int i = 0;
+ for ( ; i < 256; i++ ) {
+ if ( (*page)[i] ) {
+ pvector_reclaim( (pvector_page *) (*page)[i] );
+ }
+ }
+ free( page );
+}
+
+// Resize vector, using the reclaim function as needed, to handle any
+// excess items or to veto the resize. Returns the index of the veto, if
+// any, or <0 otherwise, with -1 indicating success and -2 indicating
+// OOM while growing.
+//
+// Nothe that resizing may result in the introduction/removal of
+// indexing levels and pages, so as to keep the leveling accurate for
+// the size.
+int pvector_resize(
+ pvector *pv,unsigned int new_size,
+ int (*reclaim)(pvector *,int,void*) )
+{
+ // Table of number of slots for a level above that of the number
+ // at the prior lower level.
+ // The first level (i.e., level 0) adds 255 slots to the one slot
+ // of no index page. Level 1 adds 255*256 slots, level 2 adds
+ // 255*(256^2), and generically level i adds 255*(256^i) slots.
+ static int level_delta[8];
+ if ( level_delta[ 0 ] == 0 ) {
+ int d = 1;
+ int i;
+ for ( i = 0; i < 8; i++ ) {
+ level_delta[ i ] = 255 * d;
+ d = 256 * d;
+ }
+ }
+ struct {
+ int old;
+ int new;
+ } level = {
+ PV_LEVELS( pv->size ),
+ PV_LEVELS( new_size )
+ };
+ if ( pv->entries == 0 ) {
+ pv->size = new_size;
+ return 0;
+ }
+ // A shrinking pvector might be veto-ed
+ if ( new_size < pv->size ) {
+ unsigned int index = new_size;
+ void **slot = pvector_next_used( pv, &index, reclaim );
+ if ( slot ) {
+ return index;
+ }
+ // At this point we know that there are no slots used after
+ // the new_size size, so now it's time to remove and reclaim
+ // any superflouous top level pages.
+ pvector_page *entries;
+ pvector_page **pp = &pv->entries;
+ while ( level.old-- > level.new ) {
+ pp = (pvector_page **)(*pp)[0];
+ }
+ if ( pp != &pv->entries ) {
+ entries = pv->entries;
+ pv->entries = *pp;
+ *pp = 0;
+ pvector_reclaim( entries );
+ }
+ } else {
+ // pvector is growing. Maybe insert levels.
+ while ( level.old < level.new ) {
+ pvector_page *p = (pvector_page *)
+ calloc( 1, sizeof( pvector_page ) );
+ if ( p == 0 ) {
+ return -2; // OOM
+ }
+ (*p)[0] = pv->entries;
+ pv->entries = p;
+ pv->size += level_delta[ level.old++ ];
+ // Note that the last level addition might make the size
+ // larger than requested, which gets corrected below.
+ }
+ }
+ pv->size = new_size;
+ return -1;
+}
+
+// Return a pointer to the indexed item the given page level, adding
+// intermediate pages if requested. Returns 0 if addition fails (OOM),
+// or if not requested and page is missing.
+// Level 0 = pointer to the item entry itself.
+// Level PVECTORLEVELS( pv->size ) - 1 =
+static void **pvector_access(
+ pvector *pv,unsigned int index,int level,int add)
+{
+ if ( index >= pv->size ) {
+ return 0;
+ }
+ void **page = (void**) &pv->entries;
+ int i = PV_LEVELS( pv->size );
+ while ( i-- > level ) {
+ if ( add && (*page) == 0 ) {
+ (*page) = calloc( 256, sizeof( void* ) );
+ }
+ page = (*page);
+ if ( page == 0 ) {
+ return 0;
+ }
+ page += ((pvector_index)index).level[ i ];
+ }
+ return page;
+}
+
+// Map index into a value slot
+void **pvector_entry(pvector *pv,unsigned int index) {
+ return pvector_access( pv, index, 0, 1 );
+}
+
+inline void pvector_set(pvector *pv,unsigned int index,void *value) {
+ void **p = pvector_entry( pv, index );
+ *p = value;
+}
+
+inline void *pvector_get(pvector *pv,unsigned int index) {
+ return *(pvector_entry( pv, index ));
+}
+
--- /dev/null
+#ifndef pvector_H
+#define pvector_H
+
+/**
+ * A pvector is a dynamic pointer array implemented as an access tree
+ * of index pages of 256 pointers.
+ */
+
+//#include <stdint.h>
+
+/*!
+ * Type: pvector_page
+ *
+ * A pvector_page is an array of 256 void* items.
+ */
+typedef void* pvector_page[256];
+
+/*!
+ * Type: pvector_index
+ *
+ * A pvector index is ether viewed in whole as an unsigned 64-bit
+ * integer, or in levels as 8 unsigned char level indexes. This
+ * implementation assumes LE integer layout.
+ */
+typedef union {
+ unsigned int whole;
+ unsigned char level[4];
+} pvector_index;
+
+/*!
+ * Type: pvector
+ *
+ * A pvector is a compound of a size and a pvector_page pointer, which
+ * when non-null points out the top-most page of the pvector. The
+ * number of levels is derived from its size with level 0 being the
+ * leaf level of actual content. E.g., a pvector larger than 256
+ * items, has at least two levels, and generally N levels may span up
+ * to 256^N content entries.
+ */
+typedef struct _pvector {
+ unsigned int size; //!< Limit for the logical entries[]
+ pvector_page *entries; //!< Pointer to entries indexing
+} pvector;
+
+// Number of page levels for size S
+#define PV_LEVELS(S) ((int)(( 39 - __builtin_clz( ((S)-1) | 1) ) / 8 ))
+
+#define PV_LEVEL_SIZE(S) ((int)(exp( 256, (S) )))
+
+// The indexing part for level part p in index i
+#define PV_PART(p,i) (((unsigned char*)&i)[p])
+
+/*!
+ * Function: int pvector_resize( pvector *pv,unsigned int new_size,
+ * int (*reclaim)(pvector *,int,void*) )
+ * \param pv
+ * \param new_size
+ * \param reclaim
+ *
+ * Tries to resize the given pvector to a new size. This may result in
+ * the introduction or removal of indexing pages, so that the leveling
+ * is consistent with the pvector size. Thus, if it grows into a new
+ * 256^N level, then one or more new upper level pages are inserted as
+ * needed. If it shrinks below the current level, then top-level pages
+ * are remove.
+ *
+ * Also, if the new size is smaller than currently, then the now
+ * excess tail of entries is scanned for any used slots and the given
+ * reclaim function is invoked successively for these. The reclaim
+ * function must, in addition to memory-managing the entry, return 0
+ * upon success and non-zero to veto the attempted pvector size
+ * change.
+ *
+ * The pvector_resize function returns 0 on success, with the size
+ * duly changed. Otherwise the function retains the current size and
+ * returns -index-1 for the index of the veto-ed entry.
+ */
+int pvector_resize(
+ pvector *pv,unsigned int new_size,
+ int (*reclaim)(pvector *,int,void*) );
+
+/*!
+ * Function: void **pvector_entry(pvector *pv,unsigned int index)
+ * \param pv - the pvector record
+ * \param index - the slot index
+ *
+ * [pgix,epix] = modulo( index, pv->page );
+ *
+ * \returns a direct pointer to the slot of the given index in the
+ * array, or 0 if the index is beyond the array limits (0-limit). Note
+ * that slot pointers are only valid while the pvector size is
+ * unchanged.
+ */
+extern void **pvector_entry(pvector *pv,unsigned int index);
+
+/*!
+ * Function: unsigned int pvector_size(pvector *pv)
+ * \param pv - the pvector record
+ * \returns the size of the pvector.
+ */
+inline unsigned int pvector_size(pvector *pv) {
+ return pv->size;
+}
+
+void pvector_set(pvector *pv,unsigned int index,void *value);
+
+void *pvector_get(pvector *pv,unsigned int index);
+
+#endif
projects / rrq / rrqmisc.git / commitdiff