From 69856f18dd51149c06d5de610a98bcfbec98f87f Mon Sep 17 00:00:00 2001 From: Celine Mercier Date: Thu, 24 Mar 2016 16:38:11 +0100 Subject: [PATCH] untested (and no possible retrieval) of CRC used to represent data in AVL trees --- python/obitools3/obidms/_obidms.cfiles | 4 +- src/crc64.c | 198 +++++++++++++++++++++++++ src/crc64.h | 9 ++ src/obiavl.c | 53 +++++-- src/obiavl.h | 5 +- 5 files changed, 252 insertions(+), 17 deletions(-) create mode 100644 src/crc64.c create mode 100644 src/crc64.h diff --git a/python/obitools3/obidms/_obidms.cfiles b/python/obitools3/obidms/_obidms.cfiles index 1fcbfd6..aa6abc7 100644 --- a/python/obitools3/obidms/_obidms.cfiles +++ b/python/obitools3/obidms/_obidms.cfiles @@ -25,4 +25,6 @@ ../../../src/bloom.c ../../../src/bloom.h ../../../src/MurmurHash2.c -../../../src/murmurhash2.h \ No newline at end of file +../../../src/murmurhash2.h +../../../src/crc64.c +../../../src/crc64.h diff --git a/src/crc64.c b/src/crc64.c new file mode 100644 index 0000000..8497f5e --- /dev/null +++ b/src/crc64.c @@ -0,0 +1,198 @@ +/* Redis uses the CRC64 variant with "Jones" coefficients and init value of 0. + * + * Specification of this CRC64 variant follows: + * Name: crc-64-jones + * Width: 64 bites + * Poly: 0xad93d23594c935a9 + * Reflected In: True + * Xor_In: 0xffffffffffffffff + * Reflected_Out: True + * Xor_Out: 0x0 + * Check("123456789"): 0xe9c6d914c4b8d9ca + * + * Copyright (c) 2012, Salvatore Sanfilippo + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * * Neither the name of Redis nor the names of its contributors may be used + * to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. */ + +#include + +static const uint64_t crc64_tab[256] = { + UINT64_C(0x0000000000000000), UINT64_C(0x7ad870c830358979), + UINT64_C(0xf5b0e190606b12f2), UINT64_C(0x8f689158505e9b8b), + UINT64_C(0xc038e5739841b68f), UINT64_C(0xbae095bba8743ff6), + UINT64_C(0x358804e3f82aa47d), UINT64_C(0x4f50742bc81f2d04), + UINT64_C(0xab28ecb46814fe75), UINT64_C(0xd1f09c7c5821770c), + UINT64_C(0x5e980d24087fec87), UINT64_C(0x24407dec384a65fe), + UINT64_C(0x6b1009c7f05548fa), UINT64_C(0x11c8790fc060c183), + UINT64_C(0x9ea0e857903e5a08), UINT64_C(0xe478989fa00bd371), + UINT64_C(0x7d08ff3b88be6f81), UINT64_C(0x07d08ff3b88be6f8), + UINT64_C(0x88b81eabe8d57d73), UINT64_C(0xf2606e63d8e0f40a), + UINT64_C(0xbd301a4810ffd90e), UINT64_C(0xc7e86a8020ca5077), + UINT64_C(0x4880fbd87094cbfc), UINT64_C(0x32588b1040a14285), + UINT64_C(0xd620138fe0aa91f4), UINT64_C(0xacf86347d09f188d), + UINT64_C(0x2390f21f80c18306), UINT64_C(0x594882d7b0f40a7f), + UINT64_C(0x1618f6fc78eb277b), UINT64_C(0x6cc0863448deae02), + UINT64_C(0xe3a8176c18803589), UINT64_C(0x997067a428b5bcf0), + UINT64_C(0xfa11fe77117cdf02), UINT64_C(0x80c98ebf2149567b), + UINT64_C(0x0fa11fe77117cdf0), UINT64_C(0x75796f2f41224489), + UINT64_C(0x3a291b04893d698d), UINT64_C(0x40f16bccb908e0f4), + UINT64_C(0xcf99fa94e9567b7f), UINT64_C(0xb5418a5cd963f206), + UINT64_C(0x513912c379682177), UINT64_C(0x2be1620b495da80e), + UINT64_C(0xa489f35319033385), UINT64_C(0xde51839b2936bafc), + UINT64_C(0x9101f7b0e12997f8), UINT64_C(0xebd98778d11c1e81), + UINT64_C(0x64b116208142850a), UINT64_C(0x1e6966e8b1770c73), + UINT64_C(0x8719014c99c2b083), UINT64_C(0xfdc17184a9f739fa), + UINT64_C(0x72a9e0dcf9a9a271), UINT64_C(0x08719014c99c2b08), + UINT64_C(0x4721e43f0183060c), UINT64_C(0x3df994f731b68f75), + UINT64_C(0xb29105af61e814fe), UINT64_C(0xc849756751dd9d87), + UINT64_C(0x2c31edf8f1d64ef6), UINT64_C(0x56e99d30c1e3c78f), + UINT64_C(0xd9810c6891bd5c04), UINT64_C(0xa3597ca0a188d57d), + UINT64_C(0xec09088b6997f879), UINT64_C(0x96d1784359a27100), + UINT64_C(0x19b9e91b09fcea8b), UINT64_C(0x636199d339c963f2), + UINT64_C(0xdf7adabd7a6e2d6f), UINT64_C(0xa5a2aa754a5ba416), + UINT64_C(0x2aca3b2d1a053f9d), UINT64_C(0x50124be52a30b6e4), + UINT64_C(0x1f423fcee22f9be0), UINT64_C(0x659a4f06d21a1299), + UINT64_C(0xeaf2de5e82448912), UINT64_C(0x902aae96b271006b), + UINT64_C(0x74523609127ad31a), UINT64_C(0x0e8a46c1224f5a63), + UINT64_C(0x81e2d7997211c1e8), UINT64_C(0xfb3aa75142244891), + UINT64_C(0xb46ad37a8a3b6595), UINT64_C(0xceb2a3b2ba0eecec), + UINT64_C(0x41da32eaea507767), UINT64_C(0x3b024222da65fe1e), + UINT64_C(0xa2722586f2d042ee), UINT64_C(0xd8aa554ec2e5cb97), + UINT64_C(0x57c2c41692bb501c), UINT64_C(0x2d1ab4dea28ed965), + UINT64_C(0x624ac0f56a91f461), UINT64_C(0x1892b03d5aa47d18), + UINT64_C(0x97fa21650afae693), UINT64_C(0xed2251ad3acf6fea), + UINT64_C(0x095ac9329ac4bc9b), UINT64_C(0x7382b9faaaf135e2), + UINT64_C(0xfcea28a2faafae69), UINT64_C(0x8632586aca9a2710), + UINT64_C(0xc9622c4102850a14), UINT64_C(0xb3ba5c8932b0836d), + UINT64_C(0x3cd2cdd162ee18e6), UINT64_C(0x460abd1952db919f), + UINT64_C(0x256b24ca6b12f26d), UINT64_C(0x5fb354025b277b14), + UINT64_C(0xd0dbc55a0b79e09f), UINT64_C(0xaa03b5923b4c69e6), + UINT64_C(0xe553c1b9f35344e2), UINT64_C(0x9f8bb171c366cd9b), + UINT64_C(0x10e3202993385610), UINT64_C(0x6a3b50e1a30ddf69), + UINT64_C(0x8e43c87e03060c18), UINT64_C(0xf49bb8b633338561), + UINT64_C(0x7bf329ee636d1eea), UINT64_C(0x012b592653589793), + UINT64_C(0x4e7b2d0d9b47ba97), UINT64_C(0x34a35dc5ab7233ee), + UINT64_C(0xbbcbcc9dfb2ca865), UINT64_C(0xc113bc55cb19211c), + UINT64_C(0x5863dbf1e3ac9dec), UINT64_C(0x22bbab39d3991495), + UINT64_C(0xadd33a6183c78f1e), UINT64_C(0xd70b4aa9b3f20667), + UINT64_C(0x985b3e827bed2b63), UINT64_C(0xe2834e4a4bd8a21a), + UINT64_C(0x6debdf121b863991), UINT64_C(0x1733afda2bb3b0e8), + UINT64_C(0xf34b37458bb86399), UINT64_C(0x8993478dbb8deae0), + UINT64_C(0x06fbd6d5ebd3716b), UINT64_C(0x7c23a61ddbe6f812), + UINT64_C(0x3373d23613f9d516), UINT64_C(0x49aba2fe23cc5c6f), + UINT64_C(0xc6c333a67392c7e4), UINT64_C(0xbc1b436e43a74e9d), + UINT64_C(0x95ac9329ac4bc9b5), UINT64_C(0xef74e3e19c7e40cc), + UINT64_C(0x601c72b9cc20db47), UINT64_C(0x1ac40271fc15523e), + UINT64_C(0x5594765a340a7f3a), UINT64_C(0x2f4c0692043ff643), + UINT64_C(0xa02497ca54616dc8), UINT64_C(0xdafce7026454e4b1), + UINT64_C(0x3e847f9dc45f37c0), UINT64_C(0x445c0f55f46abeb9), + UINT64_C(0xcb349e0da4342532), UINT64_C(0xb1eceec59401ac4b), + UINT64_C(0xfebc9aee5c1e814f), UINT64_C(0x8464ea266c2b0836), + UINT64_C(0x0b0c7b7e3c7593bd), UINT64_C(0x71d40bb60c401ac4), + UINT64_C(0xe8a46c1224f5a634), UINT64_C(0x927c1cda14c02f4d), + UINT64_C(0x1d148d82449eb4c6), UINT64_C(0x67ccfd4a74ab3dbf), + UINT64_C(0x289c8961bcb410bb), UINT64_C(0x5244f9a98c8199c2), + UINT64_C(0xdd2c68f1dcdf0249), UINT64_C(0xa7f41839ecea8b30), + UINT64_C(0x438c80a64ce15841), UINT64_C(0x3954f06e7cd4d138), + UINT64_C(0xb63c61362c8a4ab3), UINT64_C(0xcce411fe1cbfc3ca), + UINT64_C(0x83b465d5d4a0eece), UINT64_C(0xf96c151de49567b7), + UINT64_C(0x76048445b4cbfc3c), UINT64_C(0x0cdcf48d84fe7545), + UINT64_C(0x6fbd6d5ebd3716b7), UINT64_C(0x15651d968d029fce), + UINT64_C(0x9a0d8ccedd5c0445), UINT64_C(0xe0d5fc06ed698d3c), + UINT64_C(0xaf85882d2576a038), UINT64_C(0xd55df8e515432941), + UINT64_C(0x5a3569bd451db2ca), UINT64_C(0x20ed197575283bb3), + UINT64_C(0xc49581ead523e8c2), UINT64_C(0xbe4df122e51661bb), + UINT64_C(0x3125607ab548fa30), UINT64_C(0x4bfd10b2857d7349), + UINT64_C(0x04ad64994d625e4d), UINT64_C(0x7e7514517d57d734), + UINT64_C(0xf11d85092d094cbf), UINT64_C(0x8bc5f5c11d3cc5c6), + UINT64_C(0x12b5926535897936), UINT64_C(0x686de2ad05bcf04f), + UINT64_C(0xe70573f555e26bc4), UINT64_C(0x9ddd033d65d7e2bd), + UINT64_C(0xd28d7716adc8cfb9), UINT64_C(0xa85507de9dfd46c0), + UINT64_C(0x273d9686cda3dd4b), UINT64_C(0x5de5e64efd965432), + UINT64_C(0xb99d7ed15d9d8743), UINT64_C(0xc3450e196da80e3a), + UINT64_C(0x4c2d9f413df695b1), UINT64_C(0x36f5ef890dc31cc8), + UINT64_C(0x79a59ba2c5dc31cc), UINT64_C(0x037deb6af5e9b8b5), + UINT64_C(0x8c157a32a5b7233e), UINT64_C(0xf6cd0afa9582aa47), + UINT64_C(0x4ad64994d625e4da), UINT64_C(0x300e395ce6106da3), + UINT64_C(0xbf66a804b64ef628), UINT64_C(0xc5bed8cc867b7f51), + UINT64_C(0x8aeeace74e645255), UINT64_C(0xf036dc2f7e51db2c), + UINT64_C(0x7f5e4d772e0f40a7), UINT64_C(0x05863dbf1e3ac9de), + UINT64_C(0xe1fea520be311aaf), UINT64_C(0x9b26d5e88e0493d6), + UINT64_C(0x144e44b0de5a085d), UINT64_C(0x6e963478ee6f8124), + UINT64_C(0x21c640532670ac20), UINT64_C(0x5b1e309b16452559), + UINT64_C(0xd476a1c3461bbed2), UINT64_C(0xaeaed10b762e37ab), + UINT64_C(0x37deb6af5e9b8b5b), UINT64_C(0x4d06c6676eae0222), + UINT64_C(0xc26e573f3ef099a9), UINT64_C(0xb8b627f70ec510d0), + UINT64_C(0xf7e653dcc6da3dd4), UINT64_C(0x8d3e2314f6efb4ad), + UINT64_C(0x0256b24ca6b12f26), UINT64_C(0x788ec2849684a65f), + UINT64_C(0x9cf65a1b368f752e), UINT64_C(0xe62e2ad306bafc57), + UINT64_C(0x6946bb8b56e467dc), UINT64_C(0x139ecb4366d1eea5), + UINT64_C(0x5ccebf68aecec3a1), UINT64_C(0x2616cfa09efb4ad8), + UINT64_C(0xa97e5ef8cea5d153), UINT64_C(0xd3a62e30fe90582a), + UINT64_C(0xb0c7b7e3c7593bd8), UINT64_C(0xca1fc72bf76cb2a1), + UINT64_C(0x45775673a732292a), UINT64_C(0x3faf26bb9707a053), + UINT64_C(0x70ff52905f188d57), UINT64_C(0x0a2722586f2d042e), + UINT64_C(0x854fb3003f739fa5), UINT64_C(0xff97c3c80f4616dc), + UINT64_C(0x1bef5b57af4dc5ad), UINT64_C(0x61372b9f9f784cd4), + UINT64_C(0xee5fbac7cf26d75f), UINT64_C(0x9487ca0fff135e26), + UINT64_C(0xdbd7be24370c7322), UINT64_C(0xa10fceec0739fa5b), + UINT64_C(0x2e675fb4576761d0), UINT64_C(0x54bf2f7c6752e8a9), + UINT64_C(0xcdcf48d84fe75459), UINT64_C(0xb71738107fd2dd20), + UINT64_C(0x387fa9482f8c46ab), UINT64_C(0x42a7d9801fb9cfd2), + UINT64_C(0x0df7adabd7a6e2d6), UINT64_C(0x772fdd63e7936baf), + UINT64_C(0xf8474c3bb7cdf024), UINT64_C(0x829f3cf387f8795d), + UINT64_C(0x66e7a46c27f3aa2c), UINT64_C(0x1c3fd4a417c62355), + UINT64_C(0x935745fc4798b8de), UINT64_C(0xe98f353477ad31a7), + UINT64_C(0xa6df411fbfb21ca3), UINT64_C(0xdc0731d78f8795da), + UINT64_C(0x536fa08fdfd90e51), UINT64_C(0x29b7d047efec8728), +}; + + +uint64_t crc64(const unsigned char* s, uint64_t l) +{ + uint64_t j; + uint64_t crc = 0; + + for (j = 0; j < l; j++) + { + uint8_t byte = s[j]; + crc = crc64_tab[(uint8_t)crc ^ byte] ^ (crc >> 8); + } + return crc; +} + + +/* Test main */ +//#ifdef TEST_MAIN +//#include +//int main(void) { +// printf("e9c6d914c4b8d9ca == %016llx\n", +// (unsigned long long) crc64(0,(unsigned char*)"123456789",9)); +// return 0; +//} +//#endif + + diff --git a/src/crc64.h b/src/crc64.h new file mode 100644 index 0000000..7899110 --- /dev/null +++ b/src/crc64.h @@ -0,0 +1,9 @@ +/** + * @file crc64.h + * @date March 24th 2016 + * @brief Header file for CRC64 function. + */ + +#include + +uint64_t crc64(const unsigned char* s, uint64_t l); diff --git a/src/obiavl.c b/src/obiavl.c index c96e24b..6263ad7 100644 --- a/src/obiavl.c +++ b/src/obiavl.c @@ -19,9 +19,8 @@ #include #include -//#include #include "bloom.h" - +#include "crc64.h" #include "obiavl.h" #include "obierrno.h" #include "obitypes.h" @@ -692,6 +691,7 @@ AVL_node_p avl_create_node(OBIDMS_avl_p avl, index_t node_idx) node->right_child = -1; node->balance_factor = 0; node->value = -1; + node->crc64 = 0; // TODO return node; } @@ -1018,7 +1018,7 @@ int remap_an_avl(OBIDMS_avl_p avl) (avl->data)->data = mmap(NULL, ((avl->data)->header)->data_size_max, PROT_READ, - MAP_SHARED, + MAP_SHARED, // TODO test MAP_PRIVATE? avl->data_fd, ((avl->data)->header)->header_size); if ((avl->data)->data == NULL) @@ -1027,7 +1027,7 @@ int remap_an_avl(OBIDMS_avl_p avl) avl->tree = mmap(NULL, ((avl->header)->nb_items_max) * sizeof(AVL_node_t), PROT_READ, - MAP_SHARED, + MAP_SHARED, // TODO test MAP_PRIVATE? avl->avl_fd, (avl->header)->header_size); if (avl->tree == NULL) @@ -1054,8 +1054,6 @@ int obi_add_new_avl_in_group(OBIDMS_avl_group_p avl_group) // TODO check for err return -1; } - //fprintf(stderr, "\nindex length = %d, file name = %s\n", avl_idx_length, avl_name_with_idx); - (avl_group->sub_avls)[avl_group->current_avl_idx] = obi_create_avl(avl_group->dms, avl_name_with_idx); if ((avl_group->sub_avls)[avl_group->current_avl_idx] == NULL) { @@ -1578,7 +1576,8 @@ index_t insert_in_avl_group(OBIDMS_avl_group_p avl_group, byte_t* value) // TODO if ((((avl_group->sub_avls)[avl_group->current_avl_idx])->header)->nb_items == NODE_COUNT_PER_AVL) // TODO add condition with data size obi_add_new_avl_in_group(avl_group); - bloom_add(&((((avl_group->sub_avls)[avl_group->current_avl_idx])->header)->bloom_filter), value, (BYTE_ARRAY_HEADER_SIZE + *((int32_t*)(value+1)))); + bloom_add(&((((avl_group->sub_avls)[avl_group->current_avl_idx])->header)->bloom_filter), value, BYTE_ARRAY_HEADER_SIZE + *((int32_t*)(value+1))); + return obi_avl_add((avl_group->sub_avls)[avl_group->current_avl_idx], value); } @@ -1596,6 +1595,10 @@ index_t obi_avl_add(OBIDMS_avl_p avl, byte_t* value) int n = 0; int depth = 0; + uint64_t crc; + + crc = crc64(value, BYTE_ARRAY_HEADER_SIZE + ((uint64_t) (*((int32_t*)(value+1))))); // TODO warning + // Check if first node if (!((avl->header)->nb_items)) { @@ -1604,6 +1607,7 @@ index_t obi_avl_add(OBIDMS_avl_p avl, byte_t* value) // Add the value in the data array and store its index value_data_idx = avl_add_value_in_data_array(avl, value); node_to_add->value = value_data_idx; + node_to_add->crc64 = crc; // Update the number of items ((avl->header)->nb_items)++; @@ -1635,8 +1639,15 @@ index_t obi_avl_add(OBIDMS_avl_p avl, byte_t* value) parent = next; // Compare value with value of current node - to_compare = obi_avl_get(avl, current_node->value); - comp = byte_array_compare(to_compare, value); + //to_compare = obi_avl_get(avl, current_node->value); + //comp = byte_array_compare(to_compare, value); + comp = (current_node->crc64) - crc; + + if (comp == 0) + { // check if really same value + to_compare = obi_avl_get(avl, current_node->value); + comp = byte_array_compare(to_compare, value); + } if (comp > 0) // Go to left child @@ -1647,7 +1658,7 @@ index_t obi_avl_add(OBIDMS_avl_p avl, byte_t* value) else if (comp == 0) // Value already stored { - //fprintf(stderr, "\n>>>ALREADY IN, %s, %lld\n", obi_obibytes_to_seq(value), (avl->header)->nb_items); + fprintf(stderr, "\n>>>ALREADY IN, %s, %lld\n", obi_obibytes_to_seq(value), (avl->header)->nb_items); return current_node->value; // TODO should trigger error if using bloom filters } @@ -1676,6 +1687,7 @@ index_t obi_avl_add(OBIDMS_avl_p avl, byte_t* value) // Add the value in the data array and store its index value_data_idx = avl_add_value_in_data_array(avl, value); node_to_add->value = value_data_idx; + node_to_add->crc64 = crc; // Update the number of items ((avl->header)->nb_items)++; @@ -1706,7 +1718,7 @@ index_t obi_avl_add(OBIDMS_avl_p avl, byte_t* value) } -// Find if a value is already in an AVL tree TODO use bloom +// Find if a value is already in an AVL tree index_t obi_avl_find(OBIDMS_avl_p avl, byte_t* value) { int comp; @@ -1714,14 +1726,25 @@ index_t obi_avl_find(OBIDMS_avl_p avl, byte_t* value) byte_t* to_compare; AVL_node_p current_node; + uint64_t crc; + crc = crc64(value, BYTE_ARRAY_HEADER_SIZE + ((uint64_t) (*((int32_t*)(value+1))))); // TODO warning + next = (avl->header)->root_idx; while (next != -1) { current_node = (avl->tree)+next; // Compare value with value of current node - to_compare = obi_avl_get(avl, current_node->value); - comp = byte_array_compare(to_compare, value); + //to_compare = obi_avl_get(avl, current_node->value); + //comp = byte_array_compare(to_compare, value); + + comp = (current_node->crc64) - crc; + + if (comp == 0) + { // check if really same value + to_compare = obi_avl_get(avl, current_node->value); + comp = byte_array_compare(to_compare, value); + } if (comp > 0) // Go to left child @@ -1730,8 +1753,10 @@ index_t obi_avl_find(OBIDMS_avl_p avl, byte_t* value) // Go to right child next = current_node->right_child; else if (comp == 0) - // Value found + { // Value found + fprintf(stderr, "\n>>>ALREADY IN in find, %s, %lld\n", obi_obibytes_to_seq(value), (avl->header)->nb_items); return current_node->value; + } } // Value not found return -1; diff --git a/src/obiavl.h b/src/obiavl.h index cfe1c5f..663d61b 100644 --- a/src/obiavl.h +++ b/src/obiavl.h @@ -24,10 +24,10 @@ #include "obidms.h" #include "obitypes.h" - #include "bloom.h" -#define NODE_COUNT_PER_AVL (2000000) + +#define NODE_COUNT_PER_AVL (10000000) #define BLOOM_FILTER_ERROR_RATE (0.001) @@ -59,6 +59,7 @@ typedef struct AVL_node { */ index_t value; /**< Index of the value associated with the node in the data array. */ + uint64_t crc64; // TODO } AVL_node_t, *AVL_node_p;