[PATCH 1/2] bitvec: Add get/set byte sequences

The new functions bitvec_get_bytes and bitvec_set_bytes copy byte sequences from bitvecs to uint8_t arrays and vice versa. While the bytes in the bitvecs do not need to be aligned, the uint8_t arrays always are. In case the bytes in the bitvec are aligned, the implementation uses memcpy. Note that the implementation like the other existing functions assume MSB first encoding. Sponsored-by: On-Waves ehf --- include/osmocom/core/bitvec.h | 2 ++ src/bitvec.c | 75 +++++++++++++++++++++++++++++++++++++++++++ tests/Makefile.am | 9 ++++-- tests/testsuite.at | 6 ++++ 4 files changed, 90 insertions(+), 2 deletions(-) diff --git a/include/osmocom/core/bitvec.h b/include/osmocom/core/bitvec.h index 62e2e7b..445730e 100644 --- a/include/osmocom/core/bitvec.h +++ b/include/osmocom/core/bitvec.h @@ -63,5 +63,7 @@ int bitvec_set_uint(struct bitvec *bv, unsigned int in, int count); int bitvec_get_uint(struct bitvec *bv, int num_bits); int bitvec_find_bit_pos(const struct bitvec *bv, unsigned int n, enum bit_value val); int bitvec_spare_padding(struct bitvec *bv, unsigned int up_to_bit); +int bitvec_get_bytes(struct bitvec *bv, uint8_t *bytes, int count); +int bitvec_set_bytes(struct bitvec *bv, const uint8_t *bytes, int count); /*! @} */ diff --git a/src/bitvec.c b/src/bitvec.c index 8da5a48..726a768 100644 --- a/src/bitvec.c +++ b/src/bitvec.c @@ -1,6 +1,7 @@ /* bit vector utility routines */ /* (C) 2009 by Harald Welte &lt;laforge(a)gnumonks.org&gt; + * (C) 2015 by Sysmocom s.f.m.c. GmbH * * All Rights Reserved * @@ -30,6 +31,7 @@ #include <errno.h> #include <stdint.h> +#include <string.h> #include <osmocom/core/bitvec.h> @@ -261,4 +263,77 @@ int bitvec_find_bit_pos(const struct bitvec *bv, unsigned int n, return -1; } +/*! \brief get multiple bytes from current pos + * Assumes MSB first encoding. + * \param[in] bv bit vector + * \param[in] bytes array + * \param[in] count number of bytes to copy + */ +int bitvec_get_bytes(struct bitvec *bv, uint8_t *bytes, int count) +{ + int byte_offs = bytenum_from_bitnum(bv->cur_bit); + int bit_offs = bv->cur_bit % 8; + uint8_t c, last_c; + int i; + uint8_t *src; + + if (byte_offs + count + (bit_offs ? 1 : 0) > bv->data_len) + return -EINVAL; + + if (bit_offs == 0) { + memcpy(bytes, bv->data + byte_offs, count); + } else { + src = bv->data + byte_offs; + last_c = *(src++); + for (i = count; i > 0; i--) { + c = *(src++); + *(bytes++) = + (last_c << bit_offs) | + (c >> (8 - bit_offs)); + last_c = c; + } + } + + bv->cur_bit += count * 8; + return 0; +} + +/*! \brief set multiple bytes at current pos + * Assumes MSB first encoding. + * \param[in] bv bit vector + * \param[in] bytes array + * \param[in] count number of bytes to copy + */ +int bitvec_set_bytes(struct bitvec *bv, const uint8_t *bytes, int count) +{ + int byte_offs = bytenum_from_bitnum(bv->cur_bit); + int bit_offs = bv->cur_bit % 8; + uint8_t c, last_c; + int i; + uint8_t *dst; + + if (byte_offs + count + (bit_offs ? 1 : 0) > bv->data_len) + return -EINVAL; + + if (bit_offs == 0) { + memcpy(bv->data + byte_offs, bytes, count); + } else if (count > 0) { + dst = bv->data + byte_offs; + /* Get lower bits of first dst byte */ + last_c = *dst >> (8 - bit_offs); + for (i = count; i > 0; i--) { + c = *(bytes++); + *(dst++) = + (last_c << (8 - bit_offs)) | + (c >> bit_offs); + last_c = c; + } + /* Overwrite lower bits of N+1 dst byte */ + *dst = (*dst & ((1 << (8 - bit_offs)) - 1)) | + (last_c << (8 - bit_offs)); + } + + bv->cur_bit += count * 8; + return 0; +} /*! @} */ diff --git a/tests/Makefile.am b/tests/Makefile.am index 3dc9bd9..0d220e8 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -10,7 +10,8 @@ check_PROGRAMS = timer/timer_test sms/sms_test ussd/ussd_test \ kasumi/kasumi_test logging/logging_test fr/fr_test \ loggingrb/loggingrb_test strrb/strrb_test \ vty/vty_test comp128/comp128_test utils/utils_test \ - smscb/gsm0341_test stats/stats_test + smscb/gsm0341_test stats/stats_test \ + bitvec/bitvec_test if ENABLE_MSGFILE check_PROGRAMS += msgfile/msgfile_test @@ -37,6 +38,9 @@ auth_milenage_test_LDADD = $(top_builddir)/src/libosmocore.la $(top_builddir)/sr bits_bitrev_test_SOURCES = bits/bitrev_test.c bits_bitrev_test_LDADD = $(top_builddir)/src/libosmocore.la +bitvec_bitvec_test_SOURCES = bitvec/bitvec_test.c +bitvec_bitvec_test_LDADD = $(top_builddir)/src/libosmocore.la + conv_conv_test_SOURCES = conv/conv_test.c conv_conv_test_LDADD = $(top_builddir)/src/libosmocore.la @@ -124,7 +128,8 @@ EXTRA_DIST = testsuite.at $(srcdir)/package.m4 $(TESTSUITE) \ fr/fr_test.ok loggingrb/logging_test.ok \ loggingrb/logging_test.err strrb/strrb_test.ok \ vty/vty_test.ok comp128/comp128_test.ok \ - utils/utils_test.ok stats/stats_test.ok + utils/utils_test.ok stats/stats_test.ok \ + bitvec/bitvec_test.ok DISTCLEANFILES = atconfig diff --git a/tests/testsuite.at b/tests/testsuite.at index a542798..4a3fc0d 100644 --- a/tests/testsuite.at +++ b/tests/testsuite.at @@ -21,6 +21,12 @@ cat $abs_srcdir/bits/bitrev_test.ok > expout AT_CHECK([$abs_top_builddir/tests/bits/bitrev_test], [0], [expout]) AT_CLEANUP +AT_SETUP([bitvec]) +AT_KEYWORDS([bitvec]) +cat $abs_srcdir/bitvec/bitvec_test.ok > expout +AT_CHECK([$abs_top_builddir/tests/bitvec/bitvec_test], [0], [expout], [ignore]) +AT_CLEANUP + AT_SETUP([conv]) AT_KEYWORDS([conv]) cat $abs_srcdir/conv/conv_test.ok > expout -- 1.9.1