Plugging-in the ISA-L backend... Still needs more documentation and a little clean-up, but the tests are passing...

1 files changed, 591 insertions, 0 deletions

diff --git a/src/backends/isa-l/isa_l_vand.c b/src/backends/isa-l/isa_l_vand.c
new file mode 100644
index 0000000..fe11696
--- /dev/null
+++ b/src/backends/isa-l/isa_l_vand.c
@@ -0,0 +1,591 @@
+/* 
+ * Copyright 2014 Kevin M Greenan
+ *
+ * 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.  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 HOLDER 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.
+ *
+ * isa_l_rs_vand backend implementation
+ *
+ * vi: set noai tw=79 ts=4 sw=4:
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "erasurecode.h"
+#include "erasurecode_backend.h"
+#include "erasurecode_helpers.h"
+
+/* Forward declarations */
+struct ec_backend_op_stubs isa_l_rs_vand_ops;
+struct ec_backend isa_l_rs_vand;
+
+typedef void (*ec_encode_data_func)(int, int, int, unsigned char*, unsigned char **, unsigned char **);
+typedef void (*ec_init_tables_func)(int, int, unsigned char*, unsigned char *);
+typedef void (*gf_gen_rs_matrix_func)(unsigned char*, int, int);
+typedef int (*gf_invert_matrix_func)(unsigned char*, unsigned char*, const int);
+typedef unsigned char (*gf_mul_func)(unsigned char, unsigned char);
+
+struct isa_l_rs_vand_descriptor {
+    /* calls required for init */
+    ec_init_tables_func ec_init_tables;
+    gf_gen_rs_matrix_func gf_gen_rs_matrix;
+ 
+    /* calls required for encode */
+    ec_encode_data_func ec_encode_data; 
+    
+    /* calls required for decode and reconstruct */
+    gf_invert_matrix_func gf_invert_matrix;
+
+    /* multiplication function used by ISA-L */
+    gf_mul_func gf_mul;
+     
+    /* fields needed to hold state */
+    unsigned char *matrix;
+    int k;
+    int m;
+    int w;
+};
+
+static int isa_l_rs_vand_encode(void *desc, char **data, char **parity,
+        int blocksize)
+{
+    struct isa_l_rs_vand_descriptor *isa_l_desc = 
+        (struct isa_l_rs_vand_descriptor*) desc;
+
+    unsigned char *g_tbls = NULL;
+    int k = isa_l_desc->k;
+    int m = isa_l_desc->m;
+
+    // Generate g_tbls from encode matrix encode_matrix
+    g_tbls = malloc(sizeof(unsigned char) * (k * m * 32));
+    if (NULL == g_tbls) {
+        return -1;
+    }
+
+    isa_l_desc->ec_init_tables(k, m, &isa_l_desc->matrix[k * k], g_tbls);
+
+    /* FIXME - make ec_encode_data return a value */
+    isa_l_desc->ec_encode_data(blocksize, k, m, g_tbls, (unsigned char**)data,
+                               (unsigned char**)parity);
+    free(g_tbls);
+    return 0;
+}
+
+static unsigned char* isa_l_get_decode_matrix(int k, int m, unsigned char *encode_matrix, int *missing_idxs)
+{
+    int i = 0, j = 0, l = 0;
+    int n = k + m;
+    unsigned char *decode_matrix = malloc(sizeof(unsigned char) * k * k);
+    uint64_t missing_bm = convert_list_to_bitmap(missing_idxs);
+ 
+    while (i < k && l < n) {
+        if (((1 << l) & missing_bm) == 0) {
+            for (j = 0; j < k; j++) {
+                decode_matrix[(k * i) + j] = encode_matrix[(k * l) + j];
+            }
+            i++;
+        }
+        l++;
+    } 
+
+    if (i != k) {
+        free(decode_matrix);
+        decode_matrix = NULL;
+    }
+
+    return decode_matrix;
+}
+
+static int get_num_missing_elements(int *missing_idxs)
+{
+    int i = 0;
+
+    while (missing_idxs[i] > -1) {
+        i++;
+    }
+
+    return i;
+}
+
+static void mult_and_xor_row(unsigned char *to_row, 
+                             unsigned char *from_row, 
+                             unsigned char val,
+                             int num_elems,
+                             gf_mul_func gf_mul)
+{
+    int i;
+
+    for (i = 0; i < num_elems; i++) {
+        to_row[i] ^= gf_mul(val, from_row[i]);
+    }
+}
+
+/*
+ * TODO: Add in missing parity rows and adjust the inverse_rows to 
+ * be used for parity.
+ */
+static unsigned char* get_inverse_rows(int k,
+                                       int m, 
+                                       unsigned char *decode_inverse, 
+                                       unsigned char* encode_matrix, 
+                                       int *missing_idxs,
+                                       gf_mul_func gf_mul)
+{
+    uint64_t missing_bm = convert_list_to_bitmap(missing_idxs);
+    int num_missing_elements = get_num_missing_elements(missing_idxs);
+    unsigned char *inverse_rows = (unsigned char*)malloc(sizeof(unsigned
+                                    char*) * k * num_missing_elements);
+    int i, j, l = 0;
+    int n = k + m;
+
+    if (NULL == inverse_rows) {
+        return NULL;
+    }
+
+    memset(inverse_rows, 0, sizeof(unsigned
+                                    char*) * k * num_missing_elements);
+
+    /*
+     * Fill in rows for missing data
+     */
+    for (i = 0; i < k; i++) {
+        if ((1 << i) & missing_bm) { 
+            for (j = 0; j < k; j++) {
+                inverse_rows[(l * k) + j] = decode_inverse[(i * k) + j];
+            }
+            l++;
+        }
+    }
+
+    /*
+     * Process missing parity.
+     *
+     * Start with an all-zero row.
+     *
+     * For each data element, if the data element is:
+     *
+     * Available: XOR the corresponding coefficient from the
+     * encoding matrix.
+     *
+     * Unavailable: multiply corresponding coefficient with
+     * the row that corresponds to the missing data in inverse_rows
+     * and XOR the resulting row with this row.
+     */
+    for (i = k; i < n; i++) {
+        // Parity is missing
+        if ((1 << i) & missing_bm) {
+            int d_idx_avail = 0;
+            int d_idx_unavail = 0;
+            for (j = 0; j < k; j++) {
+                // This data is available, so we can use the encode matrix
+                if (((1 << j) & missing_bm) == 0) {
+                    inverse_rows[(l * k) + d_idx_avail] ^= encode_matrix[(i * k) + j];
+                    d_idx_avail++;
+                } else {
+                    mult_and_xor_row(&inverse_rows[l * k],
+                                     &inverse_rows[d_idx_unavail * k],
+                                     encode_matrix[(i * k) + j],
+                                     k,
+                                     gf_mul); 
+                    d_idx_unavail++;
+                }
+            }
+            l++;
+        }
+    }
+    return inverse_rows;
+}
+
+static int isa_l_rs_vand_decode(void *desc, char **data, char **parity,
+        int *missing_idxs, int blocksize)
+{
+    struct isa_l_rs_vand_descriptor *isa_l_desc = 
+        (struct isa_l_rs_vand_descriptor*)desc;
+
+    unsigned char *g_tbls = NULL;
+    unsigned char *decode_matrix = NULL;
+    unsigned char *decode_inverse = NULL;
+    unsigned char *inverse_rows = NULL;
+    unsigned char **decoded_elements = NULL;
+    unsigned char **available_fragments = NULL;
+    int k = isa_l_desc->k;
+    int m = isa_l_desc->m;
+    int n = k + m;
+    int ret = -1;
+    int i, j;
+
+    int num_missing_elements = get_num_missing_elements(missing_idxs);
+    uint64_t missing_bm = convert_list_to_bitmap(missing_idxs);
+
+    decode_matrix = isa_l_get_decode_matrix(k, m, isa_l_desc->matrix, missing_idxs);
+
+    if (NULL == decode_matrix) {
+        goto out;
+    }
+
+    decode_inverse = (unsigned char*)malloc(sizeof(unsigned char) * k * k);
+    
+    if (NULL == decode_inverse) {
+        goto out;
+    }
+
+    isa_l_desc->gf_invert_matrix(decode_matrix, decode_inverse, k);
+
+    // Generate g_tbls from computed decode matrix (k x k) matrix
+    g_tbls = malloc(sizeof(unsigned char) * (k * m * 32));
+    if (NULL == g_tbls) {
+        goto out;
+    }
+
+    inverse_rows = get_inverse_rows(k, m, decode_inverse, isa_l_desc->matrix, missing_idxs, isa_l_desc->gf_mul);
+
+    decoded_elements = (unsigned char**)malloc(sizeof(unsigned char*)*num_missing_elements);
+    if (NULL == decoded_elements) {
+        goto out;
+    }
+
+    available_fragments = (unsigned char**)malloc(sizeof(unsigned char*)*k);
+    if (NULL == available_fragments) {
+        goto out;
+    }
+
+    j = 0;
+    for (i = 0; i < n; i++) {
+        if (missing_bm & (1 << i)) {
+            continue;
+        } 
+        if (j == k) { 
+            break;
+        }
+        if (i < k) {
+            available_fragments[j] = (unsigned char*)data[i];
+        } else {
+            available_fragments[j] = (unsigned char*)parity[i-k];
+        }
+        j++;
+    }
+ 
+    // Grab pointers to memory needed for missing data fragments
+    j = 0;
+    for (i = 0; i < k; i++) {
+        if (missing_bm & (1 << i)) {
+            decoded_elements[j] = (unsigned char*)data[i];
+            j++;
+        }
+    }
+    for (i = k; i < n; i++) {
+        if (missing_bm & (1 << i)) {
+            decoded_elements[j] = (unsigned char*)parity[i - k];
+            j++;
+        }
+    }
+
+    isa_l_desc->ec_init_tables(k, num_missing_elements, inverse_rows, g_tbls);
+
+    isa_l_desc->ec_encode_data(blocksize, k, num_missing_elements, g_tbls, (unsigned char**)available_fragments,
+                               (unsigned char**)decoded_elements);
+
+    ret = 0;
+
+out:
+    free(g_tbls);
+    free(decode_matrix);
+    free(decode_inverse);
+    free(inverse_rows);
+    free(decoded_elements);
+    free(available_fragments);
+
+    return ret;
+}
+
+static int isa_l_rs_vand_reconstruct(void *desc, char **data, char **parity,
+        int *missing_idxs, int destination_idx, int blocksize)
+{
+    struct isa_l_rs_vand_descriptor *isa_l_desc = 
+        (struct isa_l_rs_vand_descriptor*) desc;
+    unsigned char *g_tbls = NULL;
+    unsigned char *decode_matrix = NULL;
+    unsigned char *decode_inverse = NULL;
+    unsigned char *inverse_rows = NULL;
+    unsigned char *reconstruct_buf = NULL;
+    unsigned char **available_fragments = NULL;
+    int k = isa_l_desc->k;
+    int m = isa_l_desc->m;
+    int n = k + m;
+    int ret = -1;
+    int i, j;
+    uint64_t missing_bm = convert_list_to_bitmap(missing_idxs);
+    int inverse_row = -1;
+
+    /**
+     * Get available elements and compute the inverse of their
+     * corresponding rows.
+     */
+    decode_matrix = isa_l_get_decode_matrix(k, m, isa_l_desc->matrix, missing_idxs);
+
+    if (NULL == decode_matrix) {
+        goto out;
+    }
+    
+    decode_inverse = (unsigned char*)malloc(sizeof(unsigned char) * k * k);
+    
+    if (NULL == decode_inverse) {
+        goto out;
+    }
+
+    isa_l_desc->gf_invert_matrix(decode_matrix, decode_inverse, k);
+
+    /**
+     * Get the row needed to reconstruct
+     */
+    inverse_rows = get_inverse_rows(k, m, decode_inverse, isa_l_desc->matrix, missing_idxs, isa_l_desc->gf_mul);
+
+    // Generate g_tbls from computed decode matrix (k x k) matrix
+    g_tbls = malloc(sizeof(unsigned char) * (k * m * 32));
+    if (NULL == g_tbls) {
+        goto out;
+    }
+
+    /**
+     * Fill in the available elements
+     */
+    available_fragments = (unsigned char**)malloc(sizeof(unsigned char*)*k);
+    if (NULL == available_fragments) {
+        goto out;
+    }
+
+    j = 0;
+    for (i = 0; i < n; i++) {
+        if (missing_bm & (1 << i)) {
+            continue;
+        } 
+        if (j == k) {
+          break;
+        }
+        if (i < k) {
+            available_fragments[j] = (unsigned char*)data[i];
+        } else {
+            available_fragments[j] = (unsigned char*)parity[i-k];
+        }
+        j++;
+    }
+    
+    /**
+     * Copy pointer of buffer to reconstruct
+     */
+    j = 0;
+    for (i = 0; i < n; i++) {
+        if (missing_bm & (1 << i)) {
+            if (i == destination_idx) {
+                if (i < k) {
+                    reconstruct_buf = (unsigned char*)data[i];
+                } else {
+                    reconstruct_buf = (unsigned char*)parity[i-k];
+                }
+                inverse_row = j;
+                break;
+            }
+            j++;
+        }
+    }
+
+    /**
+     * Do the reconstruction
+     */
+    isa_l_desc->ec_init_tables(k, 1, &inverse_rows[inverse_row * k], g_tbls);
+
+    isa_l_desc->ec_encode_data(blocksize, k, 1, g_tbls, (unsigned char**)available_fragments,
+                               (unsigned char**)&reconstruct_buf);
+
+    ret = 0;
+out:
+    free(g_tbls);
+    free(decode_matrix);
+    free(decode_inverse);
+    free(inverse_rows);
+    free(available_fragments);
+
+    return ret;
+}
+
+static int isa_l_rs_vand_min_fragments(void *desc, int *missing_idxs,
+        int *fragments_to_exclude, int *fragments_needed)
+{
+    struct isa_l_rs_vand_descriptor *isa_l_desc = 
+        (struct isa_l_rs_vand_descriptor*)desc;
+
+    uint64_t exclude_bm = convert_list_to_bitmap(fragments_to_exclude);
+    uint64_t missing_bm = convert_list_to_bitmap(missing_idxs) | exclude_bm;
+    int i;
+    int j = 0;
+    int ret = -1;
+
+    for (i = 0; i < (isa_l_desc->k + isa_l_desc->m); i++) {
+        if (!(missing_bm & (1 << i))) {
+            fragments_needed[j] = i;
+            j++;
+        }
+        if (j == isa_l_desc->k) {
+            ret = 0;
+            fragments_needed[j] = -1;
+            break;
+        }
+    }
+
+    return ret;
+}
+
+#define ISA_L_W 8
+static void * isa_l_rs_vand_init(struct ec_backend_args *args,
+        void *backend_sohandle)
+{
+    struct isa_l_rs_vand_descriptor *desc = NULL;
+    
+    desc = (struct isa_l_rs_vand_descriptor *)
+           malloc(sizeof(struct isa_l_rs_vand_descriptor));
+    if (NULL == desc) {
+        return NULL;
+    }
+
+    desc->k = args->uargs.k;
+    desc->m = args->uargs.m;
+    desc->w = ISA_L_W;
+
+    /* validate EC arguments */
+    {
+        long long max_symbols = 1LL << desc->w;
+        if ((desc->k + desc->m) > max_symbols) {
+            goto error;
+        }
+     }
+
+     /*
+     * ISO C forbids casting a void* to a function pointer.
+     * Since dlsym return returns a void*, we use this union to
+     * "transform" the void* to a function pointer.
+     */
+    union {
+        ec_encode_data_func encodep;
+        ec_init_tables_func init_tablesp;
+        gf_gen_rs_matrix_func gen_matrixp;
+        gf_invert_matrix_func invert_matrixp;
+        gf_mul_func gf_mulp;
+        void *vptr;
+    } func_handle = {.vptr = NULL};
+
+    /* fill in function addresses */
+    func_handle.vptr = NULL;
+    func_handle.vptr = dlsym(backend_sohandle, "ec_encode_data");
+    desc->ec_encode_data = func_handle.encodep;
+    if (NULL == desc->ec_encode_data) {
+        goto error; 
+    }
+  
+    func_handle.vptr = NULL;
+    func_handle.vptr = dlsym(backend_sohandle, "ec_init_tables");
+    desc->ec_init_tables = func_handle.init_tablesp;
+    if (NULL == desc->ec_init_tables) {
+        goto error; 
+    }
+    
+    func_handle.vptr = NULL;
+    func_handle.vptr = dlsym(backend_sohandle, "gf_gen_rs_matrix");
+    desc->gf_gen_rs_matrix = func_handle.gen_matrixp;
+    if (NULL == desc->gf_gen_rs_matrix) {
+        goto error; 
+    }
+    
+    func_handle.vptr = NULL;
+    func_handle.vptr = dlsym(backend_sohandle, "gf_invert_matrix");
+    desc->gf_invert_matrix = func_handle.invert_matrixp;
+    if (NULL == desc->gf_invert_matrix) {
+        goto error; 
+    }
+    
+    func_handle.vptr = NULL;
+    func_handle.vptr = dlsym(backend_sohandle, "gf_mul");
+    desc->gf_mul = func_handle.gf_mulp;
+    if (NULL == desc->gf_mul) {
+        goto error; 
+    }
+  
+    desc->matrix = malloc(sizeof(char) * desc->k * (desc->k + desc->m));
+    if (NULL == desc->matrix) {
+        goto error;
+    }
+
+    /**
+     * Generate ISA-L encoding matrix
+     */
+    desc->gf_gen_rs_matrix(desc->matrix, desc->k + desc->m, desc->k);
+
+    return desc;
+
+error:
+    free(desc);
+    
+    return NULL;
+}
+
+/**
+ * Return the element-size, which is the number of bits stored 
+ * on a given device, per codeword.  This is always 8 in ISA-L
+ * 
+ * Returns the size in bits!
+ */
+static int
+isa_l_rs_vand_element_size(void* desc)
+{
+  return 8;
+}
+
+static int isa_l_rs_vand_exit(void *desc)
+{
+    struct isa_l_rs_vand_descriptor *isa_l_desc = NULL;
+    
+    isa_l_desc = (struct isa_l_rs_vand_descriptor*) desc;
+
+    free(isa_l_desc);
+
+    return 0;
+}
+
+struct ec_backend_op_stubs isa_l_rs_vand_op_stubs = {
+    .INIT                       = isa_l_rs_vand_init,
+    .EXIT                       = isa_l_rs_vand_exit,
+    .ENCODE                     = isa_l_rs_vand_encode,
+    .DECODE                     = isa_l_rs_vand_decode,
+    .FRAGSNEEDED                = isa_l_rs_vand_min_fragments,
+    .RECONSTRUCT                = isa_l_rs_vand_reconstruct,
+    .ELEMENTSIZE                = isa_l_rs_vand_element_size,
+};
+
+struct ec_backend_common backend_isa_l_rs_vand = {
+    .id                         = EC_BACKEND_ISA_L_RS_VAND,
+    .name                       = "isa_l_rs_vand",
+#if defined(__MACOS__) || defined(__MACOSX__) || defined(__OSX__) || defined(__APPLE__)
+    .soname                     = "isa-l.dylib",
+#else
+    .soname                     = "isa-l.so",
+#endif
+    .soversion                  = "2.0",
+    .ops                        = &isa_l_rs_vand_op_stubs,
+};