text:
/* -*- Mode: C++; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
 *     Copyright 2010 Couchbase, Inc
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "e2espec.h"
#include "test.h"

void gen_random(char *s, const int len) {
    if (len < 1){
        return;
    }

    static const char alphanum[] =
        "0123456789"
        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
        "abcdefghijklmnopqrstuvwxyz";

    for (int i = 0; i < len; ++i) {
        s[i] = alphanum[rand() % (sizeof(alphanum) - 1)];
    }
    s[len-1] = '\0';
}

void gen_person(person_t *p){

    int klen = rand() % MAXKEY_LEN - 1;
    if(klen<=MAXITR_LEN){
        klen=MAXITR_LEN+1;
    }
    p->age = rand() % 100;
    gen_random(p->key, klen);
    gen_random(p->name, klen);
    gen_random(p->city, 12);
    gen_random(p->state, 2);
    gen_random(p->desc, 512);

}

void gen_index_params(idx_prams_t *params){
    const int len = MAXITR_LEN;
    char min[len], max[len], tmp[len];

    // generate some random range
    gen_random(min,len);
    gen_random(max,len);

    if(strcmp(max, min) < 0){
        // swap min max
        memcpy(tmp, min, strlen(min));
        memcpy(min, max, strlen(max));
        memcpy(max, tmp, strlen(max));
    }
    sprintf(params->min, "%s", min);
    sprintf(params->max, "%s", max);
}

void reset_storage_index(storage_t *st){
    gen_index_params(st->index_params);
}

void logCallbackFunc(int err_code, const char *err_msg, void *pCtxData) {
    fprintf(stderr, "%s - error code: %d, error message: %s\n",
            (char *) pCtxData, err_code, err_msg);
}

storage_t *init_storage(fdb_config *m_fconfig,
                  fdb_config *r_fconfig,
                  fdb_kvs_config *kvs_config,
                  idx_prams_t *idxp, checkpoint_t *v_chk,
                  bool walflush)
{

    storage_t *st = (storage_t *)malloc(sizeof(storage_t));
    st->v_chk = v_chk;
    st->index_params = idxp;
    st->walflush = walflush;
    st->verify_set = true;
    gen_random(st->keyspace, KEYSPACE_LEN);

    // init dbs
    fdb_open(&st->main, E2EDB_MAIN, m_fconfig);
    fdb_kvs_open(st->main, &st->all_docs, E2EKV_ALLDOCS,  kvs_config);
    fdb_kvs_open(st->main, &st->index1, E2EKV_INDEX1,  kvs_config);
    fdb_kvs_open(st->main, &st->index2, E2EKV_INDEX2,  kvs_config);
    fdb_set_log_callback(st->all_docs, logCallbackFunc,
                         (void *) "e2etest:all_docs");
    fdb_set_log_callback(st->index1, logCallbackFunc,
                         (void *) "e2etest:index1");
    fdb_set_log_callback(st->index2, logCallbackFunc,
                         (void *) "e2etest:index2");

    // use unique records db for each storage instance
    fdb_open(&st->records, E2EDB_RECORDS, r_fconfig);
    fdb_kvs_open(st->records, &st->rtx, E2EKV_RECORDS,  kvs_config);
    fdb_kvs_open(st->records, &st->chk, E2EKV_CHECKPOINTS,  kvs_config);
    fdb_set_log_callback(st->rtx, logCallbackFunc, (void *) "e2etest:rtx");
    fdb_set_log_callback(st->chk, logCallbackFunc, (void *) "e2etest:chk");
    return st;
}

void e2e_fdb_close(storage_t *st){
    fdb_close(st->main);
    fdb_close(st->records);
    free(st);
}

void e2e_fdb_shutdown(storage_t *st){
    e2e_fdb_close(st);
    fdb_shutdown();
}

void rm_storage_fs()
{
    // remove previous dummy files
    int r;
    char cmd[64];

    sprintf(cmd, SHELL_DEL" %s*>errorlog.txt", E2EDB_MAIN);
    r = system(cmd);
    (void)r;

    sprintf(cmd, SHELL_DEL" %s*>errorlog.txt", E2EDB_RECORDS);
    r = system(cmd);
    (void)r;
}

/*
 * save a transaction doc into the records db
 */
void save_tx(storage_t *st, void *key, size_t keylen, tx_type_t type){

    TEST_INIT();
    char txkey[12];
    transaction_t *tx = NULL;
    fdb_status status;

    gen_random(txkey, 12);
    tx = (transaction_t*)malloc(sizeof(transaction_t));
    memset(tx, 0, sizeof(transaction_t));
    tx->type = type;
    tx->refkey_len = keylen;
    memcpy(tx->refkey, key, keylen);

    status = fdb_set_kv(st->rtx, txkey, 12,
                        tx, sizeof(transaction_t));
    TEST_CHK(status == FDB_RESULT_SUCCESS);
    free(tx);
    tx=NULL;

}

/*
 * check whether doc is within storage index range
 *
 * TODO: custom compare
 */
bool is_indexed(idx_prams_t *idxp, person_t *p){

    char *mink = idxp->min;
    char *maxk = idxp->max;
    if ((strcmp(p->name, mink) >= 0) &&
           (strcmp(p->name, maxk) <= 0)){
            return true;
    }
    return false;
}

/*
 * 1. save a person doc into main db
 * 2. update indexes to reflect new doc
 * 3. record set transaction in records db
 */
void e2e_fdb_set_person(storage_t *st, person_t *p){

    TEST_INIT();
    fdb_status status;
    fdb_doc *doc = NULL;
    bool indexed;
    bool existed;

    strcpy(p->keyspace, st->keyspace);
    fdb_doc_create(&doc, p->key, strlen(p->key),
                   NULL, 0, (void *)p, sizeof(person_t));
    status = fdb_get(st->all_docs, doc);
    existed = (status == FDB_RESULT_SUCCESS);

    // main person.key -> person doc
    status = fdb_set(st->all_docs, doc);
    TEST_CHK(status == FDB_RESULT_SUCCESS);

    // index person.name -> person doc
    status = fdb_set_kv(st->index1, p->name, strlen(p->name), doc->key, doc->keylen);
    TEST_CHK(status == FDB_RESULT_SUCCESS);

    // index person.name -> person age
    status = fdb_set_kv(st->index2, p->name, strlen(p->name), (void *)&p->age,
                        sizeof(int));
    TEST_CHK(status == FDB_RESULT_SUCCESS);

    // update transaction db
    save_tx(st, doc->key, doc->keylen, SET_PERSON);

    if(!existed){  // new doc
        indexed = is_indexed(st->index_params, p);
        if(indexed){  // within storage index
            // update verification checkpoint
            st->v_chk->num_indexed++;
            st->v_chk->sum_age_indexed+=p->age;
            free(doc->body);
            doc->body = NULL;
            if (st->verify_set) {
                status = fdb_get(st->all_docs, doc);
                TEST_CHK(status == FDB_RESULT_SUCCESS);
            }
        }
        st->v_chk->ndocs += 1;
    }

    fdb_doc_free(doc);
    doc=NULL;

}

/*
 * 1. remove a person doc from main db
 * 2. update indexes to reflect new doc
 * 3. record delete transaction in records db
 */
void e2e_fdb_del_person(storage_t *st, person_t *p){
    TEST_INIT();

    fdb_status status;
    fdb_doc *doc = NULL;
    bool indexed;
    bool existed;

    fdb_doc_create(&doc, p->key, strlen(p->key), NULL, 0, NULL, 0);

    status = fdb_get(st->all_docs, doc);
    existed = (status == FDB_RESULT_SUCCESS);

    // main person.key -> person doc
    status = fdb_del(st->all_docs, doc);
    TEST_CHK(status == FDB_RESULT_SUCCESS);

    // index person.name -> person doc
    status = fdb_del_kv(st->index1, p->name, strlen(p->name));
    TEST_CHK(status == FDB_RESULT_SUCCESS);

    // index person.name -> person age
    status = fdb_del_kv(st->index2, p->name, strlen(p->name));
    TEST_CHK(status == FDB_RESULT_SUCCESS);

    // update transaction db
    save_tx(st, doc->key, doc->keylen, DEL_PERSON);

    if(existed){ // check if was indexed
        indexed = is_indexed(st->index_params, p);
        if(indexed){  // within storage index
            // update verification checkpoint
            st->v_chk->num_indexed--;
            st->v_chk->sum_age_indexed-=p->age;
        }
        st->v_chk->ndocs -= 1;
    }

    fdb_doc_free(doc);
    doc=NULL;

}

void e2e_fdb_commit(fdb_file_handle* fhandle, bool walflush){

    TEST_INIT();

    fdb_status status;

    if(walflush){
        status = fdb_commit(fhandle, FDB_COMMIT_MANUAL_WAL_FLUSH);
    } else { // normal
        status = fdb_commit(fhandle, FDB_COMMIT_NORMAL);
    }

    TEST_CHK(status == FDB_RESULT_SUCCESS);

}

/*
 * begin a new transaction and update storage state
 */
void start_checkpoint(storage_t *st)
{
    TEST_INIT();

    checkpoint_t *chk;
    fdb_status status;
    fdb_doc *chk_doc = NULL;

    status = fdb_begin_transaction(st->records, FDB_ISOLATION_READ_COMMITTED);
    TEST_CHK(status == FDB_RESULT_SUCCESS);

    // create opening checkpoint doc
    chk = create_checkpoint(st, START_CHECKPOINT);
    fdb_doc_create(&chk_doc, chk->key, strlen(chk->key),
                   NULL, 0, chk, sizeof(checkpoint_t));

    // save checkpoint transaction
    save_tx(st, chk_doc->key, chk_doc->keylen, START_CHECKPOINT);
    status = fdb_set(st->chk, chk_doc);
    TEST_CHK(status == FDB_RESULT_SUCCESS);

#ifdef __DEBUG_E2E
    char rbuf[256];
    sprintf(rbuf, "start checkpoint[seqno:%" _F64 "]",chk->seqnum_all);
    TEST_RESULT(rbuf);
#endif

    free(chk);
    fdb_doc_free(chk_doc);
    chk_doc=NULL;
    chk=NULL;

}

/*
 * save current state of db keeping track of last seqnum for rollback
 * also close open transactions and commit all file handles
 *
 * returns key of checkpoint doc for verification
 */
void end_checkpoint(storage_t *st)
{
    TEST_INIT();

    fdb_status status;
    fdb_doc *chk_doc = NULL;
    checkpoint_t *chk;

    // create closing checkpoint doc
    chk = create_checkpoint(st, END_CHECKPOINT);
    fdb_doc_create(&chk_doc, chk->key, strlen(chk->key),
                   NULL, 0, chk, sizeof(checkpoint_t));

    // save checkpoint transaction
    save_tx(st, chk_doc->key, chk_doc->keylen, END_CHECKPOINT);

    // end transaction and commit records db
    if(st->walflush){
        status = fdb_end_transaction(st->records, FDB_COMMIT_MANUAL_WAL_FLUSH);
    } else {
        status = fdb_end_transaction(st->records, FDB_COMMIT_NORMAL);
    }
    TEST_CHK(status == FDB_RESULT_SUCCESS);

    // save checkpoint doc
    status = fdb_set(st->chk, chk_doc);
    TEST_CHK(status == FDB_RESULT_SUCCESS);

#ifdef __DEBUG_E2E
    char rbuf[256];
    sprintf(rbuf, "end checkpoint[seqno:%" _F64 "]",chk->seqnum_all);
    TEST_RESULT(rbuf);
#endif

    free(chk);
    fdb_doc_free(chk_doc);
    chk_doc=NULL;
    chk=NULL;

}

/*
 * cancel checkpoint currently in progress
 * requires deleting docs set within this checkpoint
 * from indexes
 */
void e2e_fdb_cancel_checkpoint(storage_t *st)
{
    TEST_INIT();

    fdb_kvs_info info;
    fdb_doc *doc = NULL;
    fdb_status status;
    checkpoint_t *chk;
    char rbuf[256];

    status = fdb_get_kvs_info(st->chk, &info);
    TEST_CHK(status == FDB_RESULT_SUCCESS);

    // get last stored checkpoint
    status = fdb_doc_create(&doc, NULL, 0, NULL, 0, NULL, 0);
    TEST_CHK(status == FDB_RESULT_SUCCESS);
    doc->seqnum = info.last_seqnum;
    fdb_get_byseq(st->chk, doc);
    chk = (checkpoint_t *)doc->body;

    // last check point must be start
    TEST_CHK(chk->type == START_CHECKPOINT);

    // rollback main kv and indexes
    status = fdb_rollback(&st->all_docs, chk->seqnum_all);
    TEST_CHK(status == FDB_RESULT_SUCCESS);
    status = fdb_rollback(&st->index1, chk->seqnum_idx1);
    TEST_CHK(status == FDB_RESULT_SUCCESS);
    status = fdb_rollback(&st->index2, chk->seqnum_idx2);
    TEST_CHK(status == FDB_RESULT_SUCCESS);

    // restore checkpoint
    memcpy(st->v_chk, chk, sizeof(checkpoint_t));

    // cancel
    status = fdb_abort_transaction(st->records);
    TEST_CHK(status == FDB_RESULT_SUCCESS);

    sprintf(rbuf, "revert to checkpoint[seqno:%" _F64 "]\n",chk->seqnum_all);
    TEST_RESULT(rbuf);
}

/*
 * creates in-mem snapshots, then iterates over them
 * in-mem snapshot can be passed in for re-use
 *
 * callee must remember to close handle!
 */
fdb_kvs_handle * scan(storage_t *st, fdb_kvs_handle *reuse_kv)
{
    TEST_INIT();

    fdb_kvs_handle *snap_kv;
    idx_prams_t params;
    fdb_status status;
    fdb_iterator *it;
    fdb_doc *rdoc = NULL;

    // generate params
    gen_index_params(&params);

    // create new snapkv or reuse current
    if(reuse_kv){
        status = fdb_snapshot_open(reuse_kv, &snap_kv, FDB_SNAPSHOT_INMEM);
        TEST_CHK(status == FDB_RESULT_SUCCESS);
    } else {
        status = fdb_snapshot_open(st->index1, &snap_kv, FDB_SNAPSHOT_INMEM);
        TEST_CHK(status == FDB_RESULT_SUCCESS);
    }

    // iterate over snapkv
    status = fdb_iterator_init(snap_kv, &it, params.min, 12,
                               params.max, 12, FDB_ITR_NONE);
    if (status == FDB_RESULT_SUCCESS) {
        do {
            status = fdb_iterator_get(it, &rdoc);
            if (status == FDB_RESULT_SUCCESS){

                // make sure every doc is within requested range
                TEST_CHK(((strcmp((char *)rdoc->key,params.min) >= 0) &&
                       (strcmp((char *)rdoc->key, params.max) <= 0)));
                fdb_doc_free(rdoc);
                rdoc=NULL;
            }
        } while (fdb_iterator_next(it) != FDB_RESULT_ITERATOR_FAIL);
    }

    fdb_iterator_close(it);

    return snap_kv;
}

fdb_seqnum_t last_snap_seqnum(storage_t *st, const char *kvs_name)
{
    TEST_INIT();

    int i,k;
    bool kv_found = false;
    uint64_t num_markers;
    fdb_status status;
    fdb_seqnum_t last_seqnum;
    fdb_snapshot_info_t *markers;

    // get snapmarkers
    status = fdb_get_all_snap_markers(st->main, &markers, &num_markers);
    TEST_CHK(status == FDB_RESULT_SUCCESS);

    // start with highest seqnum marker
    for(k=0;(fdb_seqnum_t)k<num_markers;k++){
        // search each kv marker
        for(i=0;i<markers[k].num_kvs_markers;i++){
            if(strcmp(markers[k].kvs_markers[i].kv_store_name, kvs_name) == 0){
                last_seqnum = markers[k].kvs_markers[i].seqnum;
                kv_found = true;
                break;
            }
        }
        if(kv_found){ // already found
            break;
        }
    }

    status = fdb_free_snap_markers(markers, num_markers);
    TEST_CHK(status == FDB_RESULT_SUCCESS);
    TEST_CHK(kv_found);
    return last_seqnum;
}

void print_n_markers(storage_t *st, uint64_t n){
    fdb_snapshot_info_t *markers;
    uint64_t num_markers, i;
    fdb_get_all_snap_markers(st->main, &markers, &num_markers);
    for (i = 0; i < n; i++){
        printf("marker:  %" _F64"\n", markers[i].kvs_markers[0].seqnum);
    }
    fdb_free_snap_markers(markers, num_markers);
}

/*
 * make a new checkpoint doc based on state of current storage
 */
checkpoint_t* create_checkpoint(storage_t *st, tx_type_t type)
{
    TEST_INIT();

    fdb_status status;
    fdb_kvs_info info;
    fdb_iterator *it;
    fdb_doc *rdoc = NULL;
    fdb_kvs_handle *snap_kv1, *snap_kv2, *snap_all;
    char *mink = st->index_params->min;
    char *maxk = st->index_params->max;
    size_t vallen;
    person_t *p = NULL;
    checkpoint_t *chk = (checkpoint_t *)malloc(sizeof(checkpoint_t));
    memset(chk, 0, sizeof(checkpoint_t));
    status = fdb_get_kvs_info(st->chk, &info);
    TEST_CHK (status == FDB_RESULT_SUCCESS);

    // commit
    e2e_fdb_commit(st->main, st->walflush);

    // get last seqnum of main kvs and indexes
    chk->seqnum_all = last_snap_seqnum(st, E2EKV_ALLDOCS);
    chk->seqnum_idx1 = last_snap_seqnum(st, E2EKV_INDEX1);
    chk->seqnum_idx2 = last_snap_seqnum(st, E2EKV_INDEX2);;

    // generate check point stats based on current state of db
    gen_random(chk->key, 12);
    chk->ndocs = info.doc_count;
    chk->balance = 0;
    chk->type = type;

    // use snapshot based iterator
    status = fdb_snapshot_open(st->all_docs, &snap_all, chk->seqnum_all);
    TEST_CHK (status == FDB_RESULT_SUCCESS);

    status = fdb_snapshot_open(st->index1, &snap_kv1, chk->seqnum_idx1);
    TEST_CHK (status == FDB_RESULT_SUCCESS);

    status = fdb_snapshot_open(st->index2, &snap_kv2, chk->seqnum_idx2);
    TEST_CHK (status == FDB_RESULT_SUCCESS);

    status = fdb_iterator_init(snap_kv1, &it, mink, 12,
                               maxk, 12, FDB_ITR_NO_DELETES);
    if (status == FDB_RESULT_SUCCESS) {
        do {
            status = fdb_iterator_get(it, &rdoc);
            if (status == FDB_RESULT_SUCCESS){
                // doc is expected to be in range of requested keys
                TEST_CHK((strcmp((char *)rdoc->key, mink) >= 0) &&
                       (strcmp((char *)rdoc->key, maxk) <= 0));

                // do reverse lookup to main kv to check if
                // key created by current storage handle
                status = fdb_get_kv(snap_all,
                                    rdoc->body, rdoc->bodylen,
                                    (void **)&p, &vallen);
                if(status == FDB_RESULT_SUCCESS){
                    if(strcmp(p->keyspace, st->keyspace) == 0){
                        // key tracked by current st handle
                        chk->num_indexed++;

                        // get from 2nd idx
                        status = fdb_get(snap_kv2, rdoc);
                        TEST_CHK (status == FDB_RESULT_SUCCESS);
                        chk->sum_age_indexed+= *((int *)rdoc->body);
                    }
                    free(p);
                    p=NULL;
                }
                fdb_doc_free(rdoc);
                rdoc = NULL;
            }

        } while (fdb_iterator_next(it) != FDB_RESULT_ITERATOR_FAIL);
    }
#ifdef __DEBUG_E2E
    printf("[%s] mink: %s -> maxk: %s (%d docs)\n", st->keyspace, mink, maxk,
        chk->num_indexed);
#endif

    fdb_doc_free(rdoc);
    rdoc=NULL;
    fdb_iterator_close(it);
    fdb_kvs_close(snap_all);
    fdb_kvs_close(snap_kv1);
    fdb_kvs_close(snap_kv2);

    return chk;
}


text:
class CreateSales < ActiveRecord::Migration
  def self.up
    create_table :sales do |t|
      t.string :name
      t.string :address
      t.datetime :sale_date

      t.timestamps
    end
  end

  def self.down
    drop_table :sales
  end
end

redpajama_set_name: RedPajamaGithub


text:
<?php

require_once 'PHPUnit/Framework.php';

require_once dirname(__FILE__).'/../../lib/Db/Decorator.php';

/**
 * @covers Db_Decorator
 */
class Db_DecoratorTest extends PHPUnit_Framework_TestCase
{
	public function setUp()
	{
		if( ! class_exists('ConcreteDecorator'))
		{
			eval('class ConcreteDecorator extends Db_Decorator{ }');
		}
	}

	// ------------------------------------------------------------------------

	public function testAbstract()
	{
		$r = new ReflectionClass('Db_Decorator');

		$this->assertTrue($r->isAbstract());
	}

	// ------------------------------------------------------------------------

	/**
	 * @expectedException RuntimeException
	 */
	public function testGetDecoratedObject()
	{
		$d = new ConcreteDecorator();

		$d->getDecoratedObject();
	}
	/**
	 * @expectedException RuntimeException
	 */
	public function testGetDecoratedObject2()
	{
		$d = new ConcreteDecorator();

		$d->setDecoratedObject('foobar');

		$d->getDecoratedObject();
	}
	/**
	 * @expectedException RuntimeException
	 */
	public function testGetDecoratedObject3()
	{
		$d = new ConcreteDecorator();

		$d->setDecoratedObject(234);

		$d->getDecoratedObject();
	}
	/**
	 * @expectedException RuntimeException
	 */
	public function testGetDecoratedObject4()
	{
		$d = new ConcreteDecorator();

		$d->setDecoratedObject(array('foobar', 234, 'baz'));

		$d->getDecoratedObject();
	}

	// ------------------------------------------------------------------------

	public function testSetDecoratedObject()
	{
		$d = new ConcreteDecorator();

		$o = new stdClass;

		$d->setDecoratedObject($o);

		$this->assertSame($o, $d->getDecoratedObject());
	}

	// ------------------------------------------------------------------------

	/**
	 * @expectedException BadMethodCallException
	 */
	public function testDecorate()
	{
		$d = new ConcreteDecorator();

		$o = new stdClass();

		$d->setDecoratedObject($o);

		$d->some_method();
	}
	public function testDecorate2()
	{
		$d = new ConcreteDecorator();

		$o = $this->getMock('stdClass', array('test'));
		$o->expects($this->once())->method('test')->with($this->equalTo('foobar'))->will($this->returnValue('test_result'));

		$d->setDecoratedObject($o);

		$this->assertEquals('test_result', $d->test('foobar'));
	}
	public function testDecorate3()
	{
		$d = new ConcreteDecorator();

		eval('class TestMock
		{
			function __call($method, $params)
			{ }
		}');

		$o = $this->getMock('TestMock', array('__call'));

		$o->expects($this->once())->method('__call')->with($this->equalTo('test'), $this->equalTo(array('foobar')))->will($this->returnValue('test_result'));

		$d->setDecoratedObject($o);

		$this->assertEquals('test_result',  $d->test('foobar'));
	}
	public function testDecorate4()
	{
		eval('class TestDecorator extends Db_Decorator
		{
			function test()
			{
				return "from decorator";
			}
		}');

		$d = new TestDecorator();

		$o = $this->getMock('stdClass', array('test', 'test2'));

		$o->expects($this->never())->method('test');
		$o->expects($this->once())->method('test2')->with('foobar2')->will($this->returnValue('from decorated'));

		$d->setDecoratedObject($o);

		$this->assertEquals('from decorator', $d->test());
		$this->assertEquals('from decorated', $d->test2('foobar2'));
	}
}

/* End of file DecoratorTest.php */
/* Location: ./tests/Db */


text:
import cv2

def equalize_image(image):
    """
    Equalizes the given image.

    :param image: Source image
    :return: Equalized image
    """
    return cv2.equalizeHist(image)

def histogram_median(histogram, image_size):
    """
    Calculates the histogram median.

    :param histogram: Histogram
    :param image_size: Image size
    :return: Histogram median
    """
    median = 0
    for i in range(0, len(histogram)):
        median += float(histogram[i]) * float(i) / float(image_size)
    return median

def histogram_from_image(image, bin_count=256):
    """
    Calculates the histogram for the image.

    :param image: Source image
    :param bin_count: Bin count
    :return: Histogram for image
    """
    return cv2.calcHist([image], [0], None, [bin_count], [0, 256])

def histogram_from_bw_image(image, bin_count=256):
    """
    Calculates the histogram for a black/white image.

    :param image: Source image
    :param bin_count: Bin count
    :return: Histogram for image
    """
    return histogram_from_image(image, bin_count)