add pcg, break mersenne, change state structs.

Makefile

@@ -1,8 +1,8 @@
 CC = gcc
-CFLAGS = -g `pkg-config fuse --cflags --libs`
+CFLAGS = -g `pkg-config fuse --cflags --libs` -L/usr/local/lib -lpcg_random
 
 DEPS = noisebox.h
-OBJ = fuse.o zeroes.o mersenne.o
+OBJ = fuse.o zeroes.o mersenne.o pcg.o
 
 %.o: %.c $(DEPS)
 	$(CC) -c -o $@ $< $(CFLAGS)

fuse.c

@@ -1,5 +1,5 @@
 #define FUSE_USE_VERSION 30
-#define NOISER_COUNT 2
+#define NOISER_COUNT 3
 
 #include <errno.h>
 #include <fuse.h>
@@ -12,22 +12,30 @@
 #include "noisebox.h"
 
 static void* do_init(struct fuse_conn_info *conn) {
+    struct nb_context *c = malloc(sizeof(struct nb_context));
+
     Noiser** noisers = malloc(sizeof(Noiser*) * NOISER_COUNT);
     noisers[0] = zero_init();
     noisers[1] = mersenne_init();
+    noisers[2] = pcg_init();
     
-    return noisers;
+    c->noisers = noisers;
+    c->state_head = NULL;
+
+    return c;
 }
 
 static int getattr_root(struct stat *st) {
     st->st_mode = S_IFDIR | 0755;
     st->st_nlink = 2 + NOISER_COUNT;
+    printf("got attr?\n");
     return 0;
 }
 
 static int lookup_path(const char *path, Noiser **n, NoiseFile **nf) {
     struct fuse_context* c = fuse_get_context();
-    Noiser** noisers = c->private_data;
+    struct nb_context *nbc = c->private_data;
+    Noiser** noisers = nbc->noisers;
     char* buf = strdup(path);
     char *mod = strtok(buf, "/");
 
@@ -61,7 +69,6 @@ static int lookup_path(const char *path, Noiser **n, NoiseFile **nf) {
     }
 }
 
-
 static int getattr_leaf(const char *path, struct stat *st) {
     Noiser *n = NULL;
     NoiseFile *nf = NULL;
@@ -107,14 +114,76 @@ static int do_getattr(const char *path, struct stat *st) {
 
     if(strcmp(path, "/") == 0) {
         ret = getattr_root(st);
+        printf("got attr: root %i\n", ret);
     } else {
         ret = getattr_leaf(path, st);
     };
 
-
     return ret;
 }
 
+static void get_file_state(const char* path, struct fuse_file_info *fi) {
+    struct fuse_context *c = fuse_get_context();
+    struct nb_context *nbc = c->private_data;
+    struct file_state *fs = nbc->state_head;
+    if(!fs) {
+        printf("no state, it's fine.\n");
+        fi->fh = (uint64_t)NULL;
+        return;
+    }
+    while(fs->next) {
+        if(path == fs->name) {
+            fi->fh = (uint64_t)fs;
+            return;
+        }
+        fs = fs->next;
+    }
+    fi->fh = (uint64_t)NULL;
+    return;
+}
+
+static void append_file_state(struct file_state *add) {
+    struct fuse_context *c = fuse_get_context();
+    struct nb_context *nbc = c->private_data;
+    struct file_state *fs = nbc->state_head;
+    if(!fs) {
+        nbc->state_head = add;
+        return;
+    }
+    while(fs->next) {
+        fs = fs->next;
+    }
+    fs->next = add;
+    return;
+}
+
+// deletes from list, but does not free.
+static void delete_file_state(struct file_state *del) {
+    struct fuse_context *c = fuse_get_context();
+    struct nb_context *nbc = c->private_data;
+    struct file_state *fs = nbc->state_head;
+    if(fs == del) {
+        printf("head = del\n");
+        if(del->next) {
+            fs = del->next;
+        } else {
+            fs = NULL;
+        }
+        return;
+    }
+    while(fs->next) {
+        if(del == fs->next) {
+            if(del->next) {
+                fs->next = del->next;
+            } else {
+                fs->next = NULL;
+            }
+            return;
+        }
+        fs = fs->next;
+    }
+}
+
 static int do_open(const char* path, struct fuse_file_info* fi) {
     Noiser *n = NULL;
     NoiseFile *nf = NULL;
@@ -122,10 +191,43 @@ static int do_open(const char* path, struct fuse_file_info* fi) {
 
     ret = lookup_path(path, &n, &nf);
     if(ret !=0) {
+        printf("lookup_path() error");
         return ret;
     }
 
-    ret = n->do_open(path, fi);
+    // check if file is already opened.
+    get_file_state(path, fi);
+    if(fi->fh) {
+        return 0;
+    }
+
+    if(n->do_open) {
+        ret = n->do_open(path, fi);
+        append_file_state((struct file_state *)fi->fh);
+    }
+
+    return ret;
+}
+
+static int do_release(const char *path, struct fuse_file_info *fi) {
+    Noiser *n = NULL;
+    NoiseFile *nf = NULL;
+    int ret;
+
+    ret = lookup_path(path, &n, &nf);
+    if(ret !=0) {
+        printf("lookup_path() error");
+        return ret;
+    }
+
+    if(fi->fh) {
+        printf("clearing from statelist\n");
+        delete_file_state((struct file_state *)fi->fh);
+    }
+    if(n->do_release) {
+        printf("noiser-specific cleanup\n");
+        ret = n->do_release(path, fi);
+    }
     return ret;
 }
 
@@ -145,9 +247,11 @@ static int do_read(const char* path, char* buf, size_t sz, off_t offset,
 
 static int readdir_root(void *buffer, fuse_fill_dir_t filler) {
     struct fuse_context* c = fuse_get_context();
-    Noiser** noiser = c->private_data;
+    struct nb_context *nbc = c->private_data;
+    Noiser** noiser = nbc->noisers;
     int ret = 0;
     for(int i=0; i<NOISER_COUNT; i++) {
+        printf("filling noiser %i\n", i);
         ret = filler(buffer, noiser[i]->name, NULL, 0);
         if(ret != 0) {
             printf("failed to fill %s, dying\n", noiser[i]->name);
@@ -178,25 +282,23 @@ static int do_readdir(const char *path, void *buffer,
 
     int ret;
 
-    if(strcmp(path, "/") == 0) {
+    printf("doing readdir\n");
-        ret = readdir_root(buffer, filler);
-    } else {
-        // find noiser, generate appropriate files
-        struct fuse_context* c = fuse_get_context();
-        Noiser** noiser = c->private_data;
 
-        char * pathbuf = strdup(path);
+    if(strcmp(path, "/") == 0) {
-        char * toplevel = strtok(pathbuf, "/");
+        printf("calling readdir_root\n");
-        for(int i=0; i<NOISER_COUNT; i++) {
+        return readdir_root(buffer, filler);
-            if(strcmp(noiser[i]->name, toplevel) == 0) {
-                printf("found noiser: %s\n", noiser[i]->name);
-                ret = do_noiser_readdir(noiser[i], path, buffer, filler,
-                        offset, fi);
-            }
-        }
     }
 
-    return ret;
+    // find noiser, generate appropriate files
+    Noiser *n = NULL;
+    NoiseFile *nf = NULL;
+
+    ret = lookup_path(path, &n, &nf);
+    if(ret !=0) {
+        printf("lookup_path() error");
+        return ret;
+    }
+    return do_noiser_readdir(n, path, buffer, filler, offset, fi);
 }
 
 static struct fuse_operations ops = {
@@ -225,6 +327,7 @@ static struct fuse_operations ops = {
 	// int (*statfs) (const char *, struct statvfs *);
 	// int (*flush) (const char *, struct fuse_file_info *);
 	// int (*release) (const char *, struct fuse_file_info *);
+    .release = do_release,
 	// int (*fsync) (const char *, int, struct fuse_file_info *);
 	// int (*setxattr) (const char *, const char *, const char *, size_t, int);
 	// int (*getxattr) (const char *, const char *, char *, size_t);

mersenne.c

@@ -94,8 +94,9 @@ static uint32_t extract_u32(struct mt_state *state) {
 
     
 static int do_open(const char *path, struct fuse_file_info *fi) {
-    struct mt_state *state = malloc(sizeof(struct mt_state));
+    struct file_state *state = malloc(sizeof(struct file_state));
-    mt_init(state, 0);
+    mt_random_t rng;
+    mt_init(&rng, 0);
 
     fi->fh = (uint64_t)state;
     return 0;
@@ -108,17 +109,23 @@ static int do_getattr(const char *path, struct stat *st) {
 static int get_noise(size_t n, off_t offset, char* buf,
         struct fuse_file_info *fi) {
     printf("getting random bits: %i@%i (%i)\n", n, offset, n*sizeof(char));
+
+    // FIXME this is wrong.
+    struct mt_state *state = (struct mt_state *)(fi->fh);
+    float buf_ratio = (float)sizeof(char)/(float)sizeof(uint32_t);
+    if(offset != state->consumed * buf_ratio) {
+        printf("wrong offset, discarding state\n");
+    }
+    // TODO got distracted, never actually did this.
+
     uint32_t *tmp = malloc(n * sizeof(char));
     printf("allocated %i\n", sizeof(char) * n);
-
-    struct mt_state *state = (struct mt_state *)(fi->fh);
-
-    float buf_ratio = (float)sizeof(char)/(float)sizeof(uint32_t);
     int count = n * buf_ratio;
     printf("calling extract_u32 %i times (%i * %f)\n", count, n, buf_ratio);
     for(int i=0; i<count; i++) {
         tmp[i] = extract_u32(state);
     }
+
     // consumed is always in uint32_t.
     printf("advancing consumed: %i + %i\n", state->consumed, count);
     state->consumed += count;
@@ -169,6 +176,5 @@ Noiser* mersenne_init(void) {
     n->files[7]->name = "200GB";
     n->files[7]->size = 200000000000;
 
-
     return n;
 }

noisebox.h

@@ -5,6 +5,8 @@
 #include <fuse.h>
 #include <stddef.h>
 
+#include <pcg_variants.h>
+
 #ifndef NOISEBOX_H
 #define NOISEBOX_H
 
@@ -25,9 +27,31 @@ typedef struct {
     // int (*do_readdir)(const char *path, void *buffer, fuse_fill_dir_t filler,
     //         off_t offset, struct fuse_file_info *fi);
     int (*do_open)(const char *, struct fuse_file_info *);
+    int (*do_release)(const char *, struct fuse_file_info *);
 } Noiser;
 
+typedef union {
+    pcg32_random_t *pcg;
+} rng_state_t;
+
+// linked list of open file states
+struct file_state {
+    char *name;
+    rng_state_t rng;
+    size_t consumed;
+    struct file_state *next;
+    // assume prng output is some integral number of chars.
+    int char_ratio;
+};
+
+struct nb_context {
+    Noiser **noisers;
+    struct file_state *state_head;
+};
+
+
 Noiser* zero_init(void);
 Noiser* mersenne_init(void);
+Noiser* pcg_init(void);
 
 #endif

pcg.c

@@ -0,0 +1,127 @@
+/*
+ * pcg.c -- component to provide random numbers from pcg on demand.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pcg_variants.h>
+
+#include "noisebox.h"
+
+// static int do_readdir(const char *path, void *buffer,
+//             fuse_fill_dir_t filler, off_t offset, struct fuse_file_info *fi) {
+//     filler(buffer, ".", NULL, 0);
+//     filler(buffer, "..", NULL, 0);
+// }
+
+static int do_getattr(const char *path, struct stat *st) {
+    return 0;
+}
+
+static int get_state(const char *path, struct fuse_file_info *fi) {
+    return 0;
+}
+
+static int do_open(const char *path, struct fuse_file_info *fi) {
+    // only called if state isn't already inited.
+    struct file_state *state = malloc(sizeof(struct file_state));
+    pcg32_random_t p;
+    // fixed constant seed
+    pcg32_srandom_r(&p, 42u, 54u);
+
+    state->rng.pcg = &p;
+    state->next = NULL;
+    state->char_ratio = 4;
+
+    fi->fh = (uint64_t)state;
+    return 0;
+}
+
+static int do_release(const char *path, struct fuse_file_info *fi) {
+    free((void *)fi->fh);
+    return 0;
+}
+
+static int get_noise(size_t n, off_t offset, char* buf,
+        struct fuse_file_info *fi) {
+    printf("getting pcg rand: %i:%i\n", n, offset);
+    printf("sizeof buf = %zu (%zu * %i)\n", n * sizeof(char), n, sizeof(char));
+    struct file_state *fh = (struct file_state *)(fi->fh);
+
+    pcg32_random_t *rng = fh->rng.pcg;
+    
+    // if offset doesn't match, seek.
+    if(fh->consumed != offset) {
+        pcg32_advance_r(rng, offset - fh->consumed);
+        fh->consumed = offset;
+    }
+
+    uint32_t *tmp = malloc(n);
+
+    for(int i=0; (i*fh->char_ratio)<n; i++) {
+        tmp[i] = pcg32_random_r(rng);
+        // printf("got some noise, %i of %i\n", i, n);
+    }
+    fh->consumed += n;
+    memcpy(buf, tmp, n);
+
+    free(tmp);
+    printf("pcg random numbers obtained\n");
+    return n;
+}
+
+Noiser* pcg_init(void) {
+    Noiser* n = malloc(sizeof(Noiser));
+    n->name = "pcg";
+    n->state = NULL;
+    n->get_noise = get_noise;
+    n->do_open = do_open;
+    n->do_release = do_release;
+
+    // manually keep track of file count for now.
+    n->noisefile_count = 10;
+    n->files = malloc(sizeof(NoiseFile *) * n->noisefile_count);
+
+    n->files[0] = malloc(sizeof(NoiseFile));
+    n->files[0]->name = "1M";
+    n->files[0]->size = 1ULL<<20;
+
+    n->files[1] = malloc(sizeof(NoiseFile));
+    n->files[1]->name = "1G";
+    n->files[1]->size = 1ULL<<30;
+
+    n->files[2] = malloc(sizeof(NoiseFile));
+    n->files[2]->name = "100G";
+    n->files[2]->size = 100 * (1ULL<<30);
+
+    n->files[3] = malloc(sizeof(NoiseFile));
+    n->files[3]->name = "200GiB";
+    n->files[3]->size = 200 * (1ULL<<30);
+
+    n->files[4] = malloc(sizeof(NoiseFile));
+    n->files[4]->name = "400GiB";
+    n->files[4]->size = 400 * (1ULL<<30);
+
+    n->files[5] = malloc(sizeof(NoiseFile));
+    n->files[5]->name = "1GB";
+    n->files[5]->size = 1000000000;
+    
+    n->files[6] = malloc(sizeof(NoiseFile));
+    n->files[6]->name = "100GB";
+    n->files[6]->size = 100000000000;
+
+    n->files[7] = malloc(sizeof(NoiseFile));
+    n->files[7]->name = "200GB";
+    n->files[7]->size = 200000000000;
+
+    n->files[8] = malloc(sizeof(NoiseFile));
+    n->files[8]->name = "400GB";
+    n->files[8]->size = 400000000000;
+
+    n->files[9] = malloc(sizeof(NoiseFile));
+    n->files[9]->name = "800GB";
+    n->files[9]->size = 800000000000;
+
+    return n;
+}