src/server/ucx/map.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2013 Olaf Wintermann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. 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.
 */

#include <stdlib.h>
#include <string.h>

#include "map.h"

UcxMap *ucx_map_new(size_t size) {
    if(size == 0) {
        size = 16;
    }
    
    UcxMap *map = (UcxMap*)malloc(sizeof(UcxMap));
    if(map == NULL) {
        return NULL;
    }

    map->map = (UcxMapElement**)calloc(size, sizeof(UcxMapElement*));
    if(map->map == NULL) {
        free(map);
        return NULL;
    }
    map->size = size;
    map->count = 0;

    return map;
}

void ucx_map_free_elmlist(UcxMap *map) {
    for (size_t n = 0 ; n < map->size ; n++) {
        UcxMapElement *elem = map->map[n];
        if (elem != NULL) {
            do {
                UcxMapElement *next = elem->next;
                free(elem->key.data);
                free(elem);
                elem = next;
            } while (elem != NULL);
        }
    }
    free(map->map);
}

void ucx_map_free(UcxMap *map) {
    ucx_map_free_elmlist(map);
    free(map);
}

int ucx_map_copy(UcxMap *restrict from, UcxMap *restrict to,
        copy_func fnc, void *data) {
    UcxMapIterator i = ucx_map_iterator(from);
    void *value;
    UCX_MAP_FOREACH(value, i) {
        int ret = ucx_map_put(to, i.cur->key, fnc ? fnc(value, data) : value);
        if(ret != 0) {
            return 1;
        }
    }
    return 0;
}

UcxMap *ucx_map_clone(UcxMap *map, copy_func fnc, void *data) {
    size_t bs = (map->count * 5) >> 1;
    UcxMap *newmap = ucx_map_new(bs > map->size ? bs : map->size);
    if(newmap == NULL) {
        return NULL;
    }
    ucx_map_copy(map, newmap, fnc, data);
    return newmap;
}

int ucx_map_rehash(UcxMap *map) {
    size_t load = (map->size * 3) >> 2;
    if (map->count > load) {
        UcxMap oldmap;
        oldmap.map = map->map;
        oldmap.size = map->size;
        oldmap.count = map->count;
        
        map->size = (map->count * 5) >> 1;
        map->map = (UcxMapElement**)calloc(map->size, sizeof(UcxMapElement*));
        if(map->map == NULL) {
            *map = oldmap;
            return 1;
        }
        map->count = 0;
        ucx_map_copy(&oldmap, map, NULL, NULL);
        
        /* free the UcxMapElement list of oldmap */
        ucx_map_free_elmlist(&oldmap);
    }
    return 0;
}

int ucx_map_put(UcxMap *map, UcxKey key, void *data) {
    if(key.hash == 0) {
        key.hash = ucx_hash((char*)key.data, key.len);
    }

    size_t slot = key.hash%map->size;
    UcxMapElement *restrict elm = map->map[slot];
    UcxMapElement *restrict prev = NULL;

    while (elm != NULL && elm->key.hash < key.hash) {
        prev = elm;
        elm = elm->next;
    }
    
    if (elm == NULL || elm->key.hash != key.hash) {
        UcxMapElement *e = (UcxMapElement*)malloc(sizeof(UcxMapElement));
        if(e == NULL) {
            return -1;
        }
        e->key.data = NULL;
        if (prev) {
            prev->next = e;
        } else {
            map->map[slot] = e;
        }
        e->next = elm;
        elm = e;
    }
    
    if(elm->key.data == NULL) {
        void *kd = malloc(key.len);
        if (kd == NULL) {
            return -1;
        }
        memcpy(kd, key.data, key.len);
        key.data = kd;
        elm->key = key;
        map->count++;
    }
    elm->data = data;

    return 0;
}

void* ucx_map_get_and_remove(UcxMap *map, UcxKey key, _Bool remove) {
    if(key.hash == 0) {
        key.hash = ucx_hash((char*)key.data, key.len);
    }
    
    size_t slot = key.hash%map->size;
    UcxMapElement *restrict elm = map->map[slot];
    UcxMapElement *restrict pelm = NULL;
    while (elm && elm->key.hash <= key.hash) {
        if(elm->key.hash == key.hash) {
            int n = (key.len > elm->key.len) ? elm->key.len : key.len;
            if (memcmp(elm->key.data, key.data, n) == 0) {
                void *data = elm->data;
                if (remove) {
                    if (pelm) {
                        pelm->next = elm->next;
                    } else {
                        map->map[slot] = elm->next;
                    }
                    free(elm);
                    map->count--;
                }

                return data;
            }
        }
        pelm = elm;
        elm = pelm->next;
    }

    return NULL;
}

void *ucx_map_get(UcxMap *map, UcxKey key) {
    return ucx_map_get_and_remove(map, key, 0);
}

void *ucx_map_remove(UcxMap *map, UcxKey key) {
    return ucx_map_get_and_remove(map, key, 1);
}

UcxKey ucx_key(void *data, size_t len) {
    UcxKey key;
    key.data = data;
    key.len = len;
    key.hash = ucx_hash((const char*) data, len);
    return key;
}


int ucx_hash(const char *data, size_t len) {
    /* murmur hash 2 */

    int m = 0x5bd1e995;
    int r = 24;

    int h = 25 ^ len;

    int i = 0;
    while (len >= 4) {
        int k = data[i + 0] & 0xFF;
        k |= (data[i + 1] & 0xFF) << 8;
        k |= (data[i + 2] & 0xFF) << 16;
        k |= (data[i + 3] & 0xFF) << 24;

        k *= m;
        k ^= k >> r;
        k *= m;

        h *= m;
        h ^= k;

        i += 4;
        len -= 4;
    }

    switch (len) {
        case 3: h ^= (data[i + 2] & 0xFF) << 16;
        /* no break */
        case 2: h ^= (data[i + 1] & 0xFF) << 8;
        /* no break */
        case 1: h ^= (data[i + 0] & 0xFF); h *= m;
        /* no break */
    }

    h ^= h >> 13;
    h *= m;
    h ^= h >> 15;

    return h;
}

UcxMapIterator ucx_map_iterator(UcxMap *map) {
    UcxMapIterator i;
    i.map = map;
    i.cur = NULL;
    i.index = 0;
    return i;
}

int ucx_map_iter_next(UcxMapIterator *i, void **elm) {
    UcxMapElement *e = i->cur;
    
    if(e == NULL) {
        e = i->map->map[0];
    } else {
        e = e->next;
    }
    
    while(i->index < i->map->size) {
        if(e != NULL) {
            if(e->data != NULL) {
                i->cur = e;
                *elm = e->data;
                return 0;
            }

            e = e->next;
        } else {
            i->index++;
            
            if(i->index < i->map->size) {
                e = i->map->map[i->index];
            }
        }
    }
    
    return 1;
}

int ucx_map_load_enc(UcxMap *map, FILE *f, UcxAllocator allocator,
        ucx_map_coder decoder, void* decdata) {

    int c; int r, n;

    char *key, *value;

    while ((c = fgetc(f)) > 0) {
        /* Discard leading spaces and comments */
        if (c < 33) continue;
        if (c == '#' || c == '!') {
            while ((c = (char) fgetc(f)) > 0) {
                if (c == '\n') break;
            }
            continue;
        }

        /* read into key buffer */
        n = 16;
        key = (char*) malloc(n);
        r = 0;
        do {
            if (c == '=') break;
            if (r > n - 2) {
                n *= 2;
                key = (char*) realloc(key, n);
            }
            key[r] = c;
            r++;
        } while ((c = fgetc(f)) > 0);
        if (c <= 0) {
            free(key);
            return 1;
        }
        key[r] = 0;
        while (key[--r] == ' ') key[r] = 0;

        /* skip whitespaces */
        while ((c = fgetc(f)) > 0) {
            if (c > 32) break;
        }
        if (c <= 0) {
            free(key);
            return 1;
        }

        /* read into value buffer */
        n = 64;
        value = (char*) malloc(n);
        r = 0;
        do {
            if (c == '\n') break;
            if (r > n - 2) {
                n *= 2;
                value = (char*) realloc(value, n);
            }
            value[r] = c;
            r++;
        } while ((c = fgetc(f)) > 0);
        value[r] = 0;
        while (value[--r] < 33) value[r] = 0;

        if (decoder) {
            size_t decodedSize;
            void *decoded = decoder(value, decdata, &decodedSize);
            free(value);
            value = (char*) decoded;
            r = decodedSize;
        } else {
            r += 2;
            value = (char*) realloc(value, r);
        }

        if (allocator.pool) {
            void *pooledValue = allocator.malloc(allocator.pool, r);
            memcpy(pooledValue, value, r);
            free(value);
            value = (char*) pooledValue;
        }

        ucx_map_cstr_put(map, key, value);
        free(key);
    }

    return 0;
}

int ucx_map_store_enc(UcxMap *map, FILE *f,
        ucx_map_coder encoder, void *encdata) {
    UcxMapIterator iter = ucx_map_iterator(map);
    char *k, *v;
    sstr_t key, value;
    size_t written;

    UCX_MAP_FOREACH(v, iter) {
        k = (char*) iter.cur->key.data;
        key = sstrn(k, iter.cur->key.len);
        if (encoder) {
            size_t encodedSize;
            void *encoded = encoder(v, encdata, &encodedSize);
            value = sstrn((char*) encoded,encodedSize - 1);
        } else {
            value = sstr(v);
        }

        written = 0;
        written += fwrite(key.ptr, 1, key.length, f);
        written += fwrite(" = ", 1, 3, f);
        written += fwrite(value.ptr, 1, value.length, f);
        written += fwrite("\n", 1, 1, f);

        if (encoder) {
            free(value.ptr);
        }

        if (written != key.length + value.length + 4) return 1;
    }

    return 0;
}