From 5d253896d14ee760abf94b277d4a6495fd21662f Mon Sep 17 00:00:00 2001 From: Tim Cooijmans Date: Mon, 31 Oct 2022 13:14:37 +0100 Subject: [PATCH] Initial commit --- .github/workflows/generic.yaml | 43 ++++++ .github/workflows/golangci-lint.yaml | 18 +++ .github/workflows/test.yaml | 33 +++++ LICENSE | 191 +++++++++++++++++++++++++++ README.md | 4 + apply-license.sh | 21 +++ bitoffset.go | 82 ++++++++++++ bitoffset_test.go | 70 ++++++++++ check-license.sh | 23 ++++ go.mod | 3 + 10 files changed, 488 insertions(+) create mode 100644 .github/workflows/generic.yaml create mode 100644 .github/workflows/golangci-lint.yaml create mode 100644 .github/workflows/test.yaml create mode 100644 LICENSE create mode 100644 README.md create mode 100644 apply-license.sh create mode 100644 bitoffset.go create mode 100644 bitoffset_test.go create mode 100755 check-license.sh create mode 100644 go.mod diff --git a/.github/workflows/generic.yaml b/.github/workflows/generic.yaml new file mode 100644 index 0000000..76411bb --- /dev/null +++ b/.github/workflows/generic.yaml @@ -0,0 +1,43 @@ +# Copyright 2022 Stichting ThingsIX Foundation +# +# 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. +# +# SPDX-License-Identifier: Apache-2.0 + +name: 'Generic Checks' + +on: + pull_request: +jobs: + license: + name: Check if all files contain license header + runs-on: ubuntu-latest + steps: + - name: Set up Go + uses: actions/setup-go@v3 + with: + go-version: 1.19.2 + - name: Install addlicense + run: go install github.com/google/addlicense@53d978ad7e086016cadd4beb6f8a92d73fde9ad0 + - name: Check out code + uses: actions/checkout@v3 + - name: Check license headers + run: ./check-license.sh + check-commit-message-style: + name: Check commit message + runs-on: ubuntu-latest + steps: + - name: Check + uses: mristin/opinionated-commit-message@v3.0.0 + with: + allow-one-liners: 'true' diff --git a/.github/workflows/golangci-lint.yaml b/.github/workflows/golangci-lint.yaml new file mode 100644 index 0000000..44e0d3b --- /dev/null +++ b/.github/workflows/golangci-lint.yaml @@ -0,0 +1,18 @@ +name: golangci-lint +on: + pull_request: +permissions: + contents: read +jobs: + golangci: + name: lint + runs-on: ubuntu-latest + steps: + - uses: actions/setup-go@v3 + with: + go-version: 1.17 + - uses: actions/checkout@v3 + - name: golangci-lint + uses: golangci/golangci-lint-action@v3 + with: + version: v1.29 \ No newline at end of file diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml new file mode 100644 index 0000000..de18f7f --- /dev/null +++ b/.github/workflows/test.yaml @@ -0,0 +1,33 @@ +# Copyright 2022 Stichting ThingsIX Foundation +# +# 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. +# +# SPDX-License-Identifier: Apache-2.0 + +name: 'Test' + +on: + pull_request: +jobs: + test: + name: Test + runs-on: ubuntu-latest + steps: + - name: Check out code + uses: actions/checkout@v3 + - name: Set up Go + uses: actions/setup-go@v3 + with: + go-version: 1.19.2 + - name: Test + run: go test ./... \ No newline at end of file diff --git a/LICENSE b/LICENSE new file mode 100644 index 0000000..b70e4ca --- /dev/null +++ b/LICENSE @@ -0,0 +1,191 @@ + + Apache License + Version 2.0, January 2004 + https://www.apache.org/licenses/ + + TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION + + 1. Definitions. + + "License" shall mean the terms and conditions for use, reproduction, + and distribution as defined by Sections 1 through 9 of this document. + + "Licensor" shall mean the copyright owner or entity authorized by + the copyright owner that is granting the License. + + "Legal Entity" shall mean the union of the acting entity and all + other entities that control, are controlled by, or are under common + control with that entity. For the purposes of this definition, + "control" means (i) the power, direct or indirect, to cause the + direction or management of such entity, whether by contract or + otherwise, or (ii) ownership of fifty percent (50%) or more of the + outstanding shares, or (iii) beneficial ownership of such entity. + + "You" (or "Your") shall mean an individual or Legal Entity + exercising permissions granted by this License. + + "Source" form shall mean the preferred form for making modifications, + including but not limited to software source code, documentation + source, and configuration files. + + "Object" form shall mean any form resulting from mechanical + transformation or translation of a Source form, including but + not limited to compiled object code, generated documentation, + and conversions to other media types. + + "Work" shall mean the work of authorship, whether in Source or + Object form, made available under the License, as indicated by a + copyright notice that is included in or attached to the work + (an example is provided in the Appendix below). + + "Derivative Works" shall mean any work, whether in Source or Object + form, that is based on (or derived from) the Work and for which the + editorial revisions, annotations, elaborations, or other modifications + represent, as a whole, an original work of authorship. For the purposes + of this License, Derivative Works shall not include works that remain + separable from, or merely link (or bind by name) to the interfaces of, + the Work and Derivative Works thereof. + + "Contribution" shall mean any work of authorship, including + the original version of the Work and any modifications or additions + to that Work or Derivative Works thereof, that is intentionally + submitted to Licensor for inclusion in the Work by the copyright owner + or by an individual or Legal Entity authorized to submit on behalf of + the copyright owner. For the purposes of this definition, "submitted" + means any form of electronic, verbal, or written communication sent + to the Licensor or its representatives, including but not limited to + communication on electronic mailing lists, source code control systems, + and issue tracking systems that are managed by, or on behalf of, the + Licensor for the purpose of discussing and improving the Work, but + excluding communication that is conspicuously marked or otherwise + designated in writing by the copyright owner as "Not a Contribution." + + "Contributor" shall mean Licensor and any individual or Legal Entity + on behalf of whom a Contribution has been received by Licensor and + subsequently incorporated within the Work. + + 2. Grant of Copyright License. Subject to the terms and conditions of + this License, each Contributor hereby grants to You a perpetual, + worldwide, non-exclusive, no-charge, royalty-free, irrevocable + copyright license to reproduce, prepare Derivative Works of, + publicly display, publicly perform, sublicense, and distribute the + Work and such Derivative Works in Source or Object form. + + 3. Grant of Patent License. Subject to the terms and conditions of + this License, each Contributor hereby grants to You a perpetual, + worldwide, non-exclusive, no-charge, royalty-free, irrevocable + (except as stated in this section) patent license to make, have made, + use, offer to sell, sell, import, and otherwise transfer the Work, + where such license applies only to those patent claims licensable + by such Contributor that are necessarily infringed by their + Contribution(s) alone or by combination of their Contribution(s) + with the Work to which such Contribution(s) was submitted. If You + institute patent litigation against any entity (including a + cross-claim or counterclaim in a lawsuit) alleging that the Work + or a Contribution incorporated within the Work constitutes direct + or contributory patent infringement, then any patent licenses + granted to You under this License for that Work shall terminate + as of the date such litigation is filed. + + 4. Redistribution. You may reproduce and distribute copies of the + Work or Derivative Works thereof in any medium, with or without + modifications, and in Source or Object form, provided that You + meet the following conditions: + + (a) You must give any other recipients of the Work or + Derivative Works a copy of this License; and + + (b) You must cause any modified files to carry prominent notices + stating that You changed the files; and + + (c) You must retain, in the Source form of any Derivative Works + that You distribute, all copyright, patent, trademark, and + attribution notices from the Source form of the Work, + excluding those notices that do not pertain to any part of + the Derivative Works; and + + (d) If the Work includes a "NOTICE" text file as part of its + distribution, then any Derivative Works that You distribute must + include a readable copy of the attribution notices contained + within such NOTICE file, excluding those notices that do not + pertain to any part of the Derivative Works, in at least one + of the following places: within a NOTICE text file distributed + as part of the Derivative Works; within the Source form or + documentation, if provided along with the Derivative Works; or, + within a display generated by the Derivative Works, if and + wherever such third-party notices normally appear. The contents + of the NOTICE file are for informational purposes only and + do not modify the License. You may add Your own attribution + notices within Derivative Works that You distribute, alongside + or as an addendum to the NOTICE text from the Work, provided + that such additional attribution notices cannot be construed + as modifying the License. + + You may add Your own copyright statement to Your modifications and + may provide additional or different license terms and conditions + for use, reproduction, or distribution of Your modifications, or + for any such Derivative Works as a whole, provided Your use, + reproduction, and distribution of the Work otherwise complies with + the conditions stated in this License. + + 5. Submission of Contributions. Unless You explicitly state otherwise, + any Contribution intentionally submitted for inclusion in the Work + by You to the Licensor shall be under the terms and conditions of + this License, without any additional terms or conditions. + Notwithstanding the above, nothing herein shall supersede or modify + the terms of any separate license agreement you may have executed + with Licensor regarding such Contributions. + + 6. Trademarks. This License does not grant permission to use the trade + names, trademarks, service marks, or product names of the Licensor, + except as required for reasonable and customary use in describing the + origin of the Work and reproducing the content of the NOTICE file. + + 7. Disclaimer of Warranty. Unless required by applicable law or + agreed to in writing, Licensor provides the Work (and each + Contributor provides its Contributions) on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or + implied, including, without limitation, any warranties or conditions + of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A + PARTICULAR PURPOSE. You are solely responsible for determining the + appropriateness of using or redistributing the Work and assume any + risks associated with Your exercise of permissions under this License. + + 8. Limitation of Liability. In no event and under no legal theory, + whether in tort (including negligence), contract, or otherwise, + unless required by applicable law (such as deliberate and grossly + negligent acts) or agreed to in writing, shall any Contributor be + liable to You for damages, including any direct, indirect, special, + incidental, or consequential damages of any character arising as a + result of this License or out of the use or inability to use the + Work (including but not limited to damages for loss of goodwill, + work stoppage, computer failure or malfunction, or any and all + other commercial damages or losses), even if such Contributor + has been advised of the possibility of such damages. + + 9. Accepting Warranty or Additional Liability. While redistributing + the Work or Derivative Works thereof, You may choose to offer, + and charge a fee for, acceptance of support, warranty, indemnity, + or other liability obligations and/or rights consistent with this + License. However, in accepting such obligations, You may act only + on Your own behalf and on Your sole responsibility, not on behalf + of any other Contributor, and only if You agree to indemnify, + defend, and hold each Contributor harmless for any liability + incurred by, or claims asserted against, such Contributor by reason + of your accepting any such warranty or additional liability. + + END OF TERMS AND CONDITIONS + + Copyright 2013-2018 Docker, 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 + + https://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. \ No newline at end of file diff --git a/README.md b/README.md new file mode 100644 index 0000000..e04f831 --- /dev/null +++ b/README.md @@ -0,0 +1,4 @@ +# bitoffset + +This repository contains code to get and set integers at (unaligned) bit offsets in Go. Unaligned offsets are commonly used in +low-bandwidth applications to reduce transmission size. diff --git a/apply-license.sh b/apply-license.sh new file mode 100644 index 0000000..bf8dd18 --- /dev/null +++ b/apply-license.sh @@ -0,0 +1,21 @@ +#!/bin/sh +# Copyright 2022 Stichting ThingsIX Foundation +# +# 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. +# +# SPDX-License-Identifier: Apache-2.0 + + +# Adds a license to all code files, requires the https://github.com/google/addlicense tool to be installed, add ignores for code that doesn't need a license. +# Example for Go: addlicense -c "Stichting ThingsIX Foundation" -s -ignore "external/**" . +addlicense -c "Stichting ThingsIX Foundation" -s . \ No newline at end of file diff --git a/bitoffset.go b/bitoffset.go new file mode 100644 index 0000000..7b69a16 --- /dev/null +++ b/bitoffset.go @@ -0,0 +1,82 @@ +// Copyright 2022 Stichting ThingsIX Foundation +// +// 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. +// +// SPDX-License-Identifier: Apache-2.0 + +package bitoffset + +func Int32(buf []byte, pos uint32, len uint8) int32 { + ui := int32(Uint32(buf, pos, len)) + if len == 32 || (ui&(1<<(len-1)) == 0) { + return ui + } + return ui | ((^0) << len) +} + +func Uint32(buf []byte, pos uint32, len uint8) uint32 { + + var ret uint32 = 0 + + for i := pos; i < pos+uint32(len); i++ { + ret = ret << 1 // Shift the return value 1 position because there's more bits to add + ret |= uint32(((buf[i/8]) >> (7 - i%8)) & 0b01) // get the right byte (buf[i/8]) + // bit 0 is the first in the byte, we have to shift it 7 places over to get it to the last position + // last mask it with 0b01 to make sure we only get that byte + } + + return ret +} + +func Uint8(buf []byte, pos uint32, len uint8) uint8 { + var shift_offset uint8 = uint8(pos%8 + uint32(len)) + if shift_offset <= 8 { + return (buf[pos/8] >> (8 - shift_offset)) & ((1 << len) - 1) + } else { + return ((buf[pos/8] << (shift_offset % 8)) | (buf[pos/8+1] >> (16 - shift_offset))) & ((1 << len) - 1) + } +} + +func SetUint8(buf []byte, pos uint32, len uint8, val uint8) { + // pos and len are in bit position! not bytes! + + // Note that because we are setting a uint8_t we know that we never have to use more than 2 bytes. + var shift_offset uint8 = uint8(pos%8 + uint32(len)) + var mask uint8 = ((1 << len) - 1) + val = val & mask // mask value so we don't have any left over bits + if shift_offset <= 8 { + buf[pos/8] = (buf[pos/8] & ^(mask << (8 - shift_offset))) | (val << (8 - shift_offset)) + } else { + buf[pos/8] = (buf[pos/8] & ^(mask >> (shift_offset % 8))) | (val >> (shift_offset % 8)) + buf[pos/8+1] = (buf[pos/8+1] & ^(mask << (16 - shift_offset))) | (val << (16 - shift_offset)) + } + + // pos 0 len 1 + // val = 1 0 1 0 1 0 1 1 + // mask = 0 0 0 0 0 0 0 1 + // val = 0 0 0 0 0 0 0 1 + // buf = 1 0 1 0 1 0 1 0 + // +} + +func SetUint32(buf []byte, pos uint32, len uint8, val uint32) { + var mask uint32 = 1 << (len - 1) + for i := pos; i < pos+uint32(len); i++ { + if val&mask == 0 { + buf[i/8] |= 1 << (7 - i%8) + } else { + buf[i/8] &= (1 << (7 - i%8)) + } + mask >>= 1 + } +} diff --git a/bitoffset_test.go b/bitoffset_test.go new file mode 100644 index 0000000..ebb560d --- /dev/null +++ b/bitoffset_test.go @@ -0,0 +1,70 @@ +// Copyright 2022 Stichting ThingsIX Foundation +// +// 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. +// +// SPDX-License-Identifier: Apache-2.0 + +package bitoffset_test + +import ( + "testing" + + "github.com/ThingsIXFoundation/bitoffset" +) + +func TestUint32(t *testing.T) { + buf := []byte{0x01, 0x02} + got := bitoffset.Uint32(buf, 0, 8) + if got != 1 { + t.Errorf("got: %d, want %d", got, 1) + } + + got = bitoffset.Uint32(buf, 8, 8) + if got != 2 { + t.Errorf("got: %d, want %d", got, 2) + } + + buf = []byte{0x0e, 0xd1, 0x14, 0x90, 0x1b, 0xef, 0x9c, 0x2f, 0xa1, 0x54, 0x05, 0xb4, 0xed, 0x07, 0x88} + got = bitoffset.Uint32(buf, 4, 28) + if got != 3 { + t.Errorf("got: %d, want %d", got, 3) + } + +} + +func TestInt32(t *testing.T) { + buf := []byte{0xFF} + got := bitoffset.Int32(buf, 0, 8) + if got != -1 { + t.Errorf("got: %d, want %d", got, -1) + } + + buf = []byte{0xFF, 0xFF} + got = bitoffset.Int32(buf, 0, 16) + if got != -1 { + t.Errorf("got: %d, want %d", got, -1) + } + + buf = []byte{0x01, 0x01} + got = bitoffset.Int32(buf, 8, 8) + if got != 1 { + t.Errorf("got: %d, want %d", got, 1) + } + + buf = []byte{0x01, 0x01} + got = bitoffset.Int32(buf, 0, 16) + if got != 257 { + t.Errorf("got: %d, want %d", got, 257) + } + +} diff --git a/check-license.sh b/check-license.sh new file mode 100755 index 0000000..2c7ddef --- /dev/null +++ b/check-license.sh @@ -0,0 +1,23 @@ +#!/bin/sh +# Copyright 2022 Stichting ThingsIX Foundation +# +# 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. +# +# SPDX-License-Identifier: Apache-2.0 + + +# Adds a license to all code files, requires the https://github.com/google/addlicense tool to be installed +set -e + +# Example for Go: addlicense -check -c "Stichting ThingsIX Foundation" -s -ignore "external/**" . | xargs -I %s -- echo "::error file=%s,line=1::Missing license header" +addlicense -check -c "Stichting ThingsIX Foundation" -s . | xargs -I %s -- echo "::error file=%s,line=1::Missing license header" \ No newline at end of file diff --git a/go.mod b/go.mod new file mode 100644 index 0000000..7f63410 --- /dev/null +++ b/go.mod @@ -0,0 +1,3 @@ +module github.com/ThingsIXFoundation/bitoffset + +go 1.19