CN113886283A

CN113886283A - Event stream processing method, electronic device and computer readable medium

Info

Publication number: CN113886283A
Application number: CN202111153719.5A
Authority: CN
Inventors: 吴臻志; 杨哲宇
Original assignee: Beijing Lynxi Technology Co Ltd
Current assignee: Beijing Lynxi Technology Co Ltd
Priority date: 2021-09-29
Filing date: 2021-09-29
Publication date: 2022-01-04

Abstract

The present disclosure provides an event stream processing method, including: acquiring at least one event to be processed; determining a to-be-processed event as a current target event, and performing writing operation: determining a corresponding write-in memory chip from a plurality of preset memory chips according to a time interval to which a timestamp of a current target event belongs, and determining a corresponding target address according to an event object of the current target event; and accumulating and updating the data stored in the target address of the write-in memory chip according to the change value of the current target event. The present disclosure also provides an electronic device and a computer-readable medium.

Description

Event stream processing method, electronic device and computer readable medium

Technical Field

The present disclosure relates to the field of data stream processing technologies, and in particular, to an event stream processing method, an electronic device, and a computer-readable medium.

Background

An event stream, i.e. a stream of events, also called an event data stream, is a semantic record of an action or state transition that has occurred in an information system. The event stream can be applied to various scenes related to rapid change of information, such as stock futures trading, shooting of high-speed moving objects and the like, a corresponding information system can generate a large number of information events in a short time, but the processing speed of the event stream of the system is limited, and the processing output of the event is not matched with the event acquisition speed, so that the intuitive feedback of the data of the event stream is not timely.

Disclosure of Invention

The present disclosure provides an event stream processing method, an electronic device, and a computer-readable medium.

In a first aspect, the present disclosure provides an event stream processing method, including:

acquiring at least one event to be processed; the event to be processed comprises a corresponding timestamp, an event object and a change value, and is used for representing that the change value of the event object occurs at the moment of the timestamp;

determining one event to be processed as a current target event, and performing writing operation: determining a corresponding write-in memory chip from a plurality of preset memory chips according to the time interval to which the timestamp of the current target event belongs, and determining a corresponding target address according to the event object of the current target event; and accumulating and updating the data stored in the target address of the write-in memory chip according to the change value of the current target event.

In a second aspect, the present disclosure provides an electronic device comprising:

a processor comprising a plurality of memory chips;

a memory for storing one or more programs;

when the one or more programs are executed by the processor, the processor is caused to implement the event stream processing method according to the above embodiment.

In a third aspect, the present disclosure provides a computer-readable medium, on which a computer program is stored, wherein the computer program, when being executed by a processor, implements the steps in the event stream processing method according to the above embodiments.

According to the event stream processing method, the electronic device and the computer readable medium, the event to be processed can be written in by setting the plurality of memory chips and based on the corresponding relation between the timestamp and the memory chip and the corresponding relation between the time description and the target address, so that the event stream can be processed quickly and orderly; and, in some implementations, while performing the write operation, performing a read operation on the corresponding memory slice based on the pending event whose timestamp satisfies the preset first read condition, and outputting an event frame, so that the write operation and the read operation can be performed simultaneously.

It should be understood that the statements in this section do not necessarily identify key or critical features of the embodiments of the present disclosure, nor do they limit the scope of the present disclosure. Other features of the present disclosure will become apparent from the following description.

Drawings

The accompanying drawings are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the principles of the disclosure and not to limit the disclosure. The above and other features and advantages will become more apparent to those skilled in the art by describing in detail exemplary embodiments thereof with reference to the attached drawings, in which:

fig. 1 is a flowchart of an event stream processing method provided in an embodiment of the present disclosure;

FIG. 2 is a flowchart illustrating a method for implementing step S2 according to an embodiment of the present disclosure;

FIG. 3 is a flowchart illustrating a method for implementing step S3 according to an embodiment of the present disclosure;

FIG. 4 is a flowchart of a specific implementation method of step S3 in the embodiment of the present disclosure;

FIG. 5 is a flowchart illustrating another exemplary method for implementing step S3 according to an embodiment of the present disclosure;

fig. 6 is a flowchart of a specific implementation method of step S201 in the embodiment of the present disclosure;

fig. 7 is a block diagram of an event stream processing system according to an embodiment of the present disclosure;

fig. 8 is a block diagram of an electronic device according to an embodiment of the disclosure;

fig. 9 is a block diagram of a computer-readable medium according to an embodiment of the disclosure.

Detailed Description

To facilitate a better understanding of the technical aspects of the present disclosure, exemplary embodiments of the present disclosure are described below in conjunction with the accompanying drawings, wherein various details of the embodiments of the present disclosure are included to facilitate an understanding, and they should be considered as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the present disclosure. Also, descriptions of well-known functions and constructions are omitted in the following description for clarity and conciseness.

Embodiments of the present disclosure and features of embodiments may be combined with each other without conflict.

As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Fig. 1 is a flowchart of an event stream processing method according to an embodiment of the present disclosure. As shown in fig. 1, the method includes:

and step S1, acquiring at least one event to be processed.

The event to be processed comprises a corresponding timestamp, an event object and a change value, wherein the event object is also called an event description, and the event is used for representing the change value of the event object at the moment of the timestamp; specifically, the event stream is an asynchronous data stream, each transmitted event represents a change of a specific object at each acquired time node, and the timestamp, the event object, and the change value are event elements formatted by each event; in some embodiments, the timestamp, the event object, and the change value are embodied in a form of a relational tuple, for example, when the event stream is a transaction event stream, the event element of each transmitted event may include a triplet of the timestamp, the transaction object, and a transaction amount, for example, when the plurality of events to be processed are acquired by an acquisition device based on a Dynamic Vision Sensor (DVS), the event element of each event may include a quadruplet of the timestamp, a pixel coordinate (plane coordinate system), and a brightness change value.

In some embodiments, at least one event to be processed is acquired at regular time intervals; the time interval is related to the acquisition period of the event or to the system frame conversion processing speed.

In some embodiments, step S1, the step of obtaining at least one event to be processed, includes: storing the obtained event to be processed into a buffer area; in some embodiments, the buffer is a First-in-First-out (FIFO) buffer.

And step S2, determining a to-be-processed event as a current target event, and performing writing operation.

Fig. 2 is a flowchart illustrating a specific implementation method of step S2 in this disclosure. As shown in fig. 2, step S2 includes step S201 and step S202.

Step S201, determining a corresponding write memory slice from a plurality of preset memory slices according to a time interval to which a timestamp of the current target event belongs, and determining a corresponding target address according to an event object of the current target event.

In step S201, a write memory slice corresponding to the current write operation is determined according to the timestamp of the current target event, and a target address corresponding to the write operation is determined according to the event object serving as the event identification information.

In some embodiments, the events to be processed are acquired by an acquisition device based on a dynamic vision sensor, specifically, the acquisition device does not output the events according to the timestamp sequence, and the events are output out of sequence, but the timestamps of the events output within a certain time interval do not differ too much. Thus, in some embodiments, the number of memory chips is determined according to a preset maximum timestamp phase difference value, so that the maximum timestamp phase difference value is less than or equal to the number of memory chips plus 1.

Step S202, data stored in the target address written into the memory chip is updated in an accumulated mode according to the change value of the current target event.

Each memory chip corresponds to an event frame, data in each memory chip is read to generate a corresponding event frame, and each event frame reflects the change condition of a corresponding event in a certain time period, so that the pixel value in each event frame corresponds to the accumulation result of the change value written in a reading period and corresponds to the accumulation process of the change value, and the accumulation process corresponds to the data updating based on the change value; and if the plurality of events to be processed are acquired by the acquisition equipment based on the dynamic vision sensor, accumulating the brightness change values, expressing the brightness of each pixel by accumulating the events, and reflecting the relative brightness change in a short time to simulate the real-time brightness of the corresponding pixel.

In some embodiments, in step S202, the step of updating the data stored in the target address written into the memory chip according to the change value of the current target event includes: reading a current value stored in a target address written into the memory chip, inputting the current value and a change value of a current target event into the adder, and writing an output result of the adder into the target address written into the memory chip.

In some embodiments, corresponding to the above-mentioned situation that the to-be-processed event obtained in step S1 is stored in the buffer, in step S2, the step of determining that one of the to-be-processed events is the current target event includes: and acquiring the earliest stored event to be processed from the buffer area as the current target event.

In some embodiments, the method further comprises: step S3.

In step S3, when the reading condition is satisfied, a reading operation is performed.

Fig. 3 is a flowchart illustrating a specific implementation method of step S3 in this disclosure. As shown in fig. 3, step S3 includes steps S301 to S303.

Step S301 determines to read a memory slice from a plurality of memory slices.

Wherein the read memory slice is determined from the plurality of memory slices based on the corresponding read condition.

Step S302, reading data stored in each address of the read memory chip, and generating an event frame according to a mapping relationship between a preset address and an object in the frame.

The event frame represents the change value of each object in the corresponding time interval; the writing operation for writing into the memory chip is still carried out while the reading operation is carried out for reading the memory chip, thereby realizing the simultaneous framing of a plurality of event frames.

In some embodiments, objects in a frame are allocated in order from a low address to a high address to establish a mapping relationship thereof.

In some embodiments, the arrangement of the addresses of the memory chip may be embodied based on a row and column form, so that row and column information corresponding to each address may be mapped to an object in the frame.

Step S303, clear the read memory slice.

After the reading of the data stored in each address of the read memory chip is completed, writing zeros to each address of the read memory chip to empty the second memory chip, so that the read memory chip can be used for accumulating the change value of the event in the next reading period.

Fig. 4 is a flowchart illustrating a specific implementation method of step S3 in the embodiment of the present disclosure. Specifically, in an embodiment corresponding to step S301 to step S303, as shown in fig. 4, in step S3, the step of determining the corresponding target address according to the event object of the current target event includes:

step S3a, when the timestamp of the current target event meets a preset first reading condition, performing a reading operation: and determining a corresponding read memory slice from the plurality of memory slices according to the time interval to which the timestamp of the current target event belongs, reading data stored in each address of the read memory slice, and generating an event frame according to the mapping relation between a preset address and an object in the frame.

The reading memory chip and the writing memory chip are determined based on the time interval to which the timestamp of the current target event belongs, but are different from each other, the reading time corresponding to the reading memory chip is later than the writing time corresponding to the writing memory chip, and the reading time and the writing time are not in one time interval; that is, for the same memory chip, the time for reading the memory chip is later than the time for writing data into the memory chip.

In some embodiments, whether the timestamp meets a preset first reading condition may be determined according to a magnitude relationship between the timestamp of the current target event and a preset comparison threshold; and in some embodiments, the number identification of the memory chip can be determined based on the size relationship to determine to read the memory chip.

In some embodiments, when a time interval to which a timestamp of a current target event belongs is a preset any one of the reading trigger intervals, determining that the timestamp of the current target event meets a preset first reading condition; and determining the memory chip corresponding to the read trigger interval as a read memory chip. In some embodiments, all time intervals after the nth time interval from the time of starting the operation are taken as the read trigger intervals, and n is greater than or equal to 1.

Fig. 5 is a flowchart illustrating another specific implementation method of step S3 in the embodiment of the present disclosure. Specifically, in an embodiment corresponding to step S301 to step S303, as shown in fig. 5, in step S3, the step of determining the corresponding target address according to the event object of the current target event includes:

step S3b, when the system time satisfies a preset second reading condition, performing a reading operation: and determining a corresponding read memory chip from the plurality of memory chips according to the system time, reading data stored in each address of the read memory chip, and generating an event frame according to a mapping relation between a preset address and an object in the frame.

The system time is used for realizing time synchronization and clock period calibration of each module and hardware in the system; in some embodiments, the system time is generated by a corresponding timer, and the determination of whether the system time satisfies the second read condition is based on a timer triggering event.

In some embodiments, when the system time is equal to any one of the preset reading period values, determining that the system time meets a second reading condition; and determining the read memory chip corresponding to the current read cycle according to the read cycle value corresponding to the system time.

In some embodiments, for the write operation and the read operation described in embodiments of the present disclosure, it includes: inputting the target address to an arbiter, and indicating a memory chip corresponding to a write operation and a read operation to the arbiter; the arbiter decides to write or read the corresponding address in each memory chip.

The embodiment of the disclosure provides an event stream processing method, which can perform write operation on an event to be processed by setting a plurality of memory chips and based on the corresponding relation between a timestamp and the memory chips and the corresponding relation between time description and a target address, thereby realizing rapid and ordered processing of an event stream; and, in some implementations, while performing the write operation, performing a read operation on the corresponding memory slice based on the pending event whose timestamp satisfies the preset first read condition, and outputting an event frame, so that the write operation and the read operation can be performed simultaneously.

Fig. 6 is a flowchart of a specific implementation method of step S201 in the embodiment of the present disclosure. Specifically, the event to be processed is acquired by acquisition equipment based on a dynamic visual sensor, the event object comprises pixel coordinates, and the change value comprises a brightness change value; as shown in fig. 6, in step S201, the step of determining the corresponding target address according to the event object of the current target event includes:

and step S2011, inputting the pixel coordinate corresponding to the current target event to a spatial downsampling mapper.

The pixel coordinates corresponding to the input current target event are input into a spatial down-sampling mapper for down-sampling, so that the input pixel coordinates meet the requirements of the size and the coordinate system of the output event frame image, and the event frame is convenient to generate.

Step S2012, determining a target address according to the output result of the spatial downsampling mapper and a preset address mapping coefficient.

And mapping the pixel coordinate corresponding to the downsampled current target event into the address of the memory chip based on the corresponding address mapping coefficient, so that an event frame can be generated according to the mapping relation between the address of the memory chip and the object in the frame.

The event stream processing method provided by the present disclosure is described in detail below in conjunction with practical applications.

Fig. 7 is a block diagram of an event stream processing system according to an embodiment of the present disclosure. As shown in fig. 7, the event stream processing system includes: the memory array comprises an arbiter and a plurality of memory chips (each rectangle filled with black in the figure), wherein the memory chips are exemplarily shown in five in number; the arrows in the figure show the data transfer direction.

Specifically, each time a preset time interval passes, a plurality of events to be processed which are collected by the collecting device and stored in the buffer area are obtained, wherein the buffer is a first-in first-out buffer, the controller is configured to control address generation and write-in enabling of the buffer and the memory array, each event to be processed includes a timestamp, an event object, and a change value corresponding to the event, illustratively, the dynamic vision sensor-based acquisition device continuously acquires and outputs a stream of events to be processed during working time, the specifically transmitted event object corresponding to each event to be processed is a pixel coordinate (plane coordinate system), the change value corresponding to each event to be processed is a brightness change value, thus, the event element of each event to be processed includes a quadruple (x, y, Δ pt, t) of pixel coordinates (x, y), a luminance change value Δ pt, and a time stamp t.

After that, the parameter determination flow of the write operation is performed: determining a to-be-processed event as a current target event, acquiring a quadruple (x, y, Δ pt, t) corresponding to the current target event, inputting the quadruple (x, y, Δ pt, t) to a write control module aiming at a timestamp t of the current target event, and determining a number identifier r1 of a corresponding memory chip by the write control module based on a formula r1 ═ t/Δ t mod N to determine the corresponding write memory chip, namely a first memory chip r1, wherein Δ t is a preset time interval, and N is the number of the memory chips; and inputting the pixel coordinates (x, y) to a spatial down-sampling mapper, outputting the result (x) of the spatial down-sampling mapper_d,y_d) And the target address addrA is determined by the address mapping module according to a preset address mapping coefficient W based on a formula addrA ═ yd × W + xd.

Meanwhile, a parameter determination process for reading operation is performed: for a quadruple (x, y, Δ pt, t) corresponding to a current target event, performing a reading operation when a timestamp t of the current target event meets a preset first reading condition, wherein the timestamp t of the current target event is input to a reading switching and enabling control module, and when the module detects that the timestamp t of the current target event is within a preset reading trigger interval, determining that the timestamp t of the event to be processed meets the first reading condition, specifically, the timestamp t is increased in value along with the lapse of system time, and in some embodiments, the timestamp t is set in a cycle; and the read switching and enabling control module determines a second memory chip r2 corresponding to the current read period according to the read trigger interval corresponding to the timestamp t of the current target event, takes the second memory chip r2 as a read memory chip, performs read enabling, and controls the read address generation module to continuously generate the read address addrB.

Then, the memory array makes a determination for a write operation and a read operation: inputting the serial number identifier r1 of the first memory chip, the serial number identifier r2 of the second memory chip, the target address addrA and the read address addrB into an arbiter, and determining to write or read the corresponding address in each memory chip by the arbiter, so that the current value p stored in the target address addrA of the first memory chip r1 is read for writing the target address addrA of the first memory chip r1, the current value p and the brightness change value Δ pt of the current target event are input into an adder ADD, and the output result Δ pt + p of the adder ADD is written into the target address addrA of the first memory chip r 1; and reading data in the second memory slice r2 according to the continuously generated reading address addrB, generating and outputting an event frame data according to the mapping relation between a preset address and an object in the frame, then emptying the second memory slice r2, wherein the output event frame data is influenced by a validity indication valid output by the reading switching and enabling control module, and when the validity indication valid is 1, the output event frame data is valid.

Fig. 8 is a block diagram of an electronic device according to an embodiment of the present disclosure. As shown in fig. 8, the electronic apparatus includes:

a processor 101, the processor 101 comprising a plurality of memory chips;

a memory 102 on which one or more programs are stored, which, when executed by the processor, cause the processor 101 to implement the event stream processing method according to any one of the above embodiments;

one or more I/O interfaces 103 coupled between the processor and the memory and configured to enable information interaction between the processor and the memory.

The processor 101 is a device with data processing capability, and includes but is not limited to a Central Processing Unit (CPU) and the like; memory 102 is a device having data storage capabilities including, but not limited to, random access memory (RAM, more specifically SDRAM, DDR, etc.), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), FLASH memory (FLASH); the I/O interface (read/write interface) 203 is connected between the processor 101 and the memory 102, and can realize information interaction between the processor 101 and the memory 102, which includes but is not limited to a data Bus (Bus) and the like.

In some embodiments, the processor 101, memory 102, and I/O interface 103 are interconnected via a bus 104, which in turn connects with other components of the computing device.

In some embodiments, the plurality of processors 101 includes a plurality of Graphics Processors (GPUs) arranged in combination to form a graphics processor array.

Fig. 9 is a block diagram of a computer-readable medium according to an embodiment of the disclosure. The computer readable medium has a computer program stored thereon, wherein the computer program realizes the steps of the event stream processing method according to any one of the above embodiments when executed by a processor.

It will be understood by those of ordinary skill in the art that all or some of the steps of the methods, systems, functional modules/units in the devices disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof. In a hardware implementation, the division between functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed by several physical components in cooperation. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as is well known to those of ordinary skill in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by a computer. In addition, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to those skilled in the art.

Example embodiments have been disclosed herein, and although specific terms are employed, they are used and should be interpreted in a generic and descriptive sense only and not for purposes of limitation. In some instances, features, characteristics and/or elements described in connection with a particular embodiment may be used alone or in combination with features, characteristics and/or elements described in connection with other embodiments, unless expressly stated otherwise, as would be apparent to one skilled in the art. Accordingly, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the disclosure as set forth in the appended claims.

Claims

1. An event stream processing method, comprising:

2. The event stream processing method according to claim 1, further comprising:

when the reading condition is satisfied, performing a reading operation: determining a read memory chip from the plurality of memory chips, reading data stored in each address of the read memory chip, generating an event frame according to a mapping relation between a preset address and an object in the frame, and emptying the read memory chip; the event frames characterize the change value of each object over its corresponding time interval.

3. The event stream processing method according to claim 2, wherein the performing a read operation when a read condition is satisfied includes:

when the timestamp of the current target event meets a preset first reading condition, performing reading operation: and determining the corresponding read memory chip from the plurality of memory chips according to the time interval to which the timestamp of the current target event belongs, reading data stored in each address of the read memory chip, and generating the event frame according to the mapping relation between a preset address and an object in the frame.

4. The event stream processing method according to claim 3, wherein the performing a read operation when the timestamp of the current target event satisfies a preset first read condition comprises:

when the time interval to which the timestamp of the current target event belongs is any preset reading trigger interval, determining that the timestamp of the current target event meets a preset first reading condition; and determining the memory chip corresponding to the read trigger interval as the read memory chip.

5. The event stream processing method according to claim 2, wherein the performing a read operation when a read condition is satisfied includes:

when the system time meets a preset second reading condition, performing reading operation: and determining the corresponding read memory chip from the plurality of memory chips according to the system time, reading data stored in each address of the read memory chip, and generating the event frame according to a mapping relation between a preset address and an object in the frame.

6. The event stream processing method according to claim 5, wherein the performing a reading operation when the system time satisfies a preset second reading condition comprises:

when the system time is equal to any preset reading period value, determining that the system time meets the second reading condition; and determining the read memory chip corresponding to the current read cycle according to the read cycle value corresponding to the system time.

7. The event stream processing method according to claim 2, wherein the write operation and the read operation include:

indicating a memory chip corresponding to a write operation and a read operation to an arbiter, and inputting addresses corresponding to the write operation and the read operation to the arbiter;

and the arbiter determines to write or read the corresponding address in each memory chip.

8. The event stream processing method according to claim 1, wherein the plurality of events to be processed are acquired by an acquisition device based on a dynamic visual sensor; the event object includes pixel coordinates and the variation value includes a luminance variation value.

9. The event stream processing method according to claim 8, wherein the determining the corresponding target address according to the event object of the current target event includes:

inputting the pixel coordinate corresponding to the current target event to a spatial down-sampling mapper;

and determining a target address according to the output result of the spatial downsampling mapper and a preset address mapping coefficient.

10. The event stream processing method according to claim 1, wherein the acquiring at least one event to be processed includes:

storing the obtained event to be processed into a buffer area;

the determining that one of the events to be processed is a current target event includes:

and acquiring the earliest stored event to be processed from the buffer area as the current target event.

11. The event stream processing method according to claim 1, wherein the updating, in an accumulated manner, data stored in the target address of the write memory chip according to the change value of the current target event includes:

reading a current value stored in the target address of the write-in memory chip, inputting the current value and a change value of the current target event to an adder, and writing an output result of the adder into the target address of the write-in memory chip.

12. An electronic device, comprising:

a processor comprising a plurality of memory chips;

a memory for storing one or more programs;

when executed by the processor, the one or more programs cause the processor to implement the event stream processing method of any of claims 1-11.

13. A computer-readable medium, on which a computer program is stored, wherein the computer program realizes the steps in the event stream processing method according to any of claims 1-11 when being executed by a processor.